From 48b7c2ca9df1ce470cb6245bc55852d53b89807c Mon Sep 17 00:00:00 2001
From: "Davide P. Cervone" <dpvc@union.edu>
Date: Tue, 7 Apr 2026 10:21:22 -0400
Subject: [PATCH 1/2] Work around Safari bug with negative margins used in
 bussproofs.  (mathjax/MathJax#3547)

---
 .../tex/__snapshots__/Bussproofs.test.ts.snap | 181 ++++++------------
 ts/input/tex/bussproofs/BussproofsUtil.ts     |  37 ++--
 2 files changed, 73 insertions(+), 145 deletions(-)

diff --git a/testsuite/tests/input/tex/__snapshots__/Bussproofs.test.ts.snap b/testsuite/tests/input/tex/__snapshots__/Bussproofs.test.ts.snap
index f30adfc1e..78e77a56a 100644
--- a/testsuite/tests/input/tex/__snapshots__/Bussproofs.test.ts.snap
+++ b/testsuite/tests/input/tex/__snapshots__/Bussproofs.test.ts.snap
@@ -616,8 +616,7 @@ exports[`BussproofsRegInf Unary Inference Abbr 1`] = `
 
 exports[`BussproofsRegProofs Extreme 1`] = `
 "<math xmlns="http://www.w3.org/1998/Math/MathML" data-latex="\\begin{prooftree}\\LL{HHHHH}\\RL{11111111111111111}\\AxiomC{D}\\AxiomC{A1}\\AxiomC{A2}\\TrinaryInfC{Q}\\RightLabel{AAAA}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}\\LL{qqqq}\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\LeftLabel{BBBB}\\RightLabel{MMM}\\BinaryInfC{E}\\RightLabel{CCCCC}\\LL{WWW}\\BinaryInfC{F}\\RightLabel{QERE}\\AxiomC{M}\\LL{BBB}\\BinaryInfC{$N \\rightarrow R$}\\RightLabel{Nowhere}\\end{prooftree}" display="block">
-  <mrow semantics="bspr_inference:2;bspr_proof:true;bspr_labelledRule:both">
-    <mspace width="16.317em"></mspace>
+  <mrow style="margin-left: 16.317em" semantics="bspr_inference:2;bspr_proof:true;bspr_labelledRule:both">
     <mrow data-latex="\\begin{prooftree}\\LL{HHHHH}\\RL{11111111111111111}\\AxiomC{D}\\AxiomC{A1}\\AxiomC{A2}\\TrinaryInfC{Q}\\RightLabel{AAAA}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}\\LL{qqqq}\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\LeftLabel{BBBB}\\RightLabel{MMM}\\BinaryInfC{E}\\RightLabel{CCCCC}\\LL{WWW}\\BinaryInfC{F}\\RightLabel{QERE}\\AxiomC{M}\\LL{BBB}\\BinaryInfC{$N \\rightarrow R$}\\RightLabel{Nowhere}\\end{prooftree}">
       <mpadded height=".25em" depth="+.25em" width="+.5ex" voffset="-.25em" semantics="bspr_prooflabel:left">
         <mstyle displaystyle="false">
@@ -630,10 +629,8 @@ exports[`BussproofsRegProofs Extreme 1`] = `
             <mtable framespacing="0 0">
               <mtr>
                 <mtd rowalign="bottom">
-                  <mrow semantics="bspr_inference:2;bspr_labelledRule:both">
-                    <mspace width="-18.656em"></mspace>
-                    <mrow>
-                      <mspace width="3.94em"></mspace>
+                  <mrow style="margin-left: -18.656em" semantics="bspr_inference:2;bspr_labelledRule:both">
+                    <mrow style="margin-left: 3.94em">
                       <mrow data-latex="\\RightLabel{QERE}">
                         <mpadded height=".25em" depth="+.25em" width="+.5ex" voffset="-.25em" semantics="bspr_prooflabel:left">
                           <mtext>WWW</mtext>
@@ -644,8 +641,7 @@ exports[`BussproofsRegProofs Extreme 1`] = `
                               <mtable framespacing="0 0">
                                 <mtr>
                                   <mtd rowalign="bottom">
-                                    <mrow semantics="bspr_inference:3;bspr_labelledRule:both">
-                                      <mspace width="-7.239em"></mspace>
+                                    <mrow style="margin-left: -7.239em" semantics="bspr_inference:3;bspr_labelledRule:both">
                                       <mrow data-latex="\\RightLabel{AAAA}">
                                         <mpadded height=".25em" depth="+.25em" width="+.5ex" voffset="-.25em" semantics="bspr_prooflabel:left">
                                           <mtext>HHHHH</mtext>
@@ -700,7 +696,7 @@ exports[`BussproofsRegProofs Extreme 1`] = `
                                   </mtd>
                                   <mtd></mtd>
                                   <mtd rowalign="bottom">
-                                    <mrow semantics="bspr_inference:2;bspr_labelledRule:both">
+                                    <mrow style="margin-right: -7.925em" semantics="bspr_inference:2;bspr_labelledRule:both">
                                       <mrow data-latex="\\LL{WWW}">
                                         <mpadded height=".25em" depth="+.25em" width="+.5ex" voffset="-.25em" semantics="bspr_prooflabel:left">
                                           <mtext>BBBB</mtext>
@@ -719,7 +715,7 @@ exports[`BussproofsRegProofs Extreme 1`] = `
                                                   </mtd>
                                                   <mtd></mtd>
                                                   <mtd rowalign="bottom">
-                                                    <mrow semantics="bspr_inference:2;bspr_labelledRule:both">
+                                                    <mrow style="margin-right: -3.216em" semantics="bspr_inference:2;bspr_labelledRule:both">
                                                       <mrow data-latex="\\RightLabel{MMM}">
                                                         <mpadded height=".25em" depth="+.25em" width="+.5ex" voffset="-.25em" semantics="bspr_prooflabel:left">
                                                           <mtext>qqqq</mtext>
@@ -768,7 +764,6 @@ exports[`BussproofsRegProofs Extreme 1`] = `
                                                           <mtext>AAAA</mtext>
                                                         </mpadded>
                                                       </mrow>
-                                                      <mspace width="-3.216em"></mspace>
                                                     </mrow>
                                                   </mtd>
                                                 </mtr>
@@ -789,7 +784,6 @@ exports[`BussproofsRegProofs Extreme 1`] = `
                                           <mtext>MMM</mtext>
                                         </mpadded>
                                       </mrow>
-                                      <mspace width="-7.925em"></mspace>
                                     </mrow>
                                   </mtd>
                                 </mtr>
@@ -853,22 +847,18 @@ exports[`BussproofsRegProofs Extreme 1`] = `
 
 exports[`BussproofsRegProofs Proof Complex 1`] = `
 "<math xmlns="http://www.w3.org/1998/Math/MathML" data-latex="\\begin{prooftree}\\AXC{}\\RL{$Hyp^{1}$}\\UIC{$P$}\\AXC{$P\\rightarrow Q$}\\RL{$\\rightarrow_E$}\\solidLine\\BIC{$Q^2$}\\AXC{$Q\\rightarrow R$} \\RL{$\\rightarrow_E$} \\BIC{$R$} \\AXC{$Q$}\\RL{Rit$^2$} \\UIC{$Q$}\\RL{$\\wedge_I$}\\BIC{$Q\\wedge R$}\\RL{\${\\rightarrow_I}^1$}\\UIC{$P\\rightarrow Q\\wedge R$}\\end{prooftree}" display="block">
-  <mrow semantics="bspr_inference:1;bspr_proof:true;bspr_labelledRule:right">
-    <mrow>
-      <mspace width="13.25em"></mspace>
-      <mrow data-latex="\\begin{prooftree}\\AXC{}\\RL{$Hyp^{1}$}\\UIC{$P$}\\AXC{$P\\rightarrow Q$}\\RL{$\\rightarrow_E$}\\solidLine\\BIC{$Q^2$}\\AXC{$Q\\rightarrow R$} \\RL{$\\rightarrow_E$} \\BIC{$R$} \\AXC{$Q$}\\RL{Rit$^2$} \\UIC{$Q$}\\RL{$\\wedge_I$}\\BIC{$Q\\wedge R$}\\RL{\${\\rightarrow_I}^1$}\\UIC{$P\\rightarrow Q\\wedge R$}\\end{prooftree}">
-        <mspace width="-1.155em"></mspace>
+  <mrow style="margin-right: 2.953em" semantics="bspr_inference:1;bspr_proof:true;bspr_labelledRule:right">
+    <mrow style="margin-left: 13.25em">
+      <mrow data-latex="\\begin{prooftree}\\AXC{}\\RL{$Hyp^{1}$}\\UIC{$P$}\\AXC{$P\\rightarrow Q$}\\RL{$\\rightarrow_E$}\\solidLine\\BIC{$Q^2$}\\AXC{$Q\\rightarrow R$} \\RL{$\\rightarrow_E$} \\BIC{$R$} \\AXC{$Q$}\\RL{Rit$^2$} \\UIC{$Q$}\\RL{$\\wedge_I$}\\BIC{$Q\\wedge R$}\\RL{\${\\rightarrow_I}^1$}\\UIC{$P\\rightarrow Q\\wedge R$}\\end{prooftree}" style="margin-left: -1.155em">
         <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
           <mtr>
             <mtd>
               <mtable framespacing="0 0">
                 <mtr>
                   <mtd rowalign="bottom">
-                    <mrow semantics="bspr_inference:2;bspr_labelledRule:right">
-                      <mrow>
-                        <mspace width="-13.25em"></mspace>
-                        <mrow>
-                          <mspace width="9.111em"></mspace>
+                    <mrow style="margin-right: -5.456em" semantics="bspr_inference:2;bspr_labelledRule:right">
+                      <mrow style="margin-left: -13.25em">
+                        <mrow style="margin-left: 9.111em">
                           <mrow data-latex="\\RL{\${\\rightarrow_I}^1$}">
                             <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
                               <mtr>
@@ -876,10 +866,8 @@ exports[`BussproofsRegProofs Proof Complex 1`] = `
                                   <mtable framespacing="0 0">
                                     <mtr>
                                       <mtd rowalign="bottom">
-                                        <mrow semantics="bspr_inference:2;bspr_labelledRule:right">
-                                          <mspace width="-9.111em"></mspace>
-                                          <mrow>
-                                            <mspace width="3.592em"></mspace>
+                                        <mrow style="margin-left: -9.111em" semantics="bspr_inference:2;bspr_labelledRule:right">
+                                          <mrow style="margin-left: 3.592em">
                                             <mrow data-latex="\\BIC{$R$}">
                                               <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
                                                 <mtr>
@@ -887,8 +875,7 @@ exports[`BussproofsRegProofs Proof Complex 1`] = `
                                                     <mtable framespacing="0 0">
                                                       <mtr>
                                                         <mtd rowalign="bottom">
-                                                          <mrow semantics="bspr_inference:2;bspr_labelledRule:right">
-                                                            <mspace width="-3.592em"></mspace>
+                                                          <mrow style="margin-left: -3.592em" semantics="bspr_inference:2;bspr_labelledRule:right">
                                                             <mrow data-latex="\\BIC{$Q^2$}">
                                                               <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
                                                                 <mtr>
@@ -1019,7 +1006,7 @@ exports[`BussproofsRegProofs Proof Complex 1`] = `
                                       </mtd>
                                       <mtd></mtd>
                                       <mtd rowalign="bottom">
-                                        <mrow semantics="bspr_inference:1;bspr_labelledRule:right">
+                                        <mrow style="margin-right: -2.055em" semantics="bspr_inference:1;bspr_labelledRule:right">
                                           <mrow data-latex="\\RL{$\\wedge_I$}">
                                             <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
                                               <mtr>
@@ -1063,7 +1050,6 @@ exports[`BussproofsRegProofs Proof Complex 1`] = `
                                               </mstyle>
                                             </mpadded>
                                           </mrow>
-                                          <mspace width="-2.055em"></mspace>
                                         </mrow>
                                       </mtd>
                                     </mtr>
@@ -1095,7 +1081,6 @@ exports[`BussproofsRegProofs Proof Complex 1`] = `
                           </mrow>
                         </mrow>
                       </mrow>
-                      <mspace width="-5.456em"></mspace>
                     </mrow>
                   </mtd>
                 </mtr>
@@ -1135,29 +1120,24 @@ exports[`BussproofsRegProofs Proof Complex 1`] = `
         </mpadded>
       </mrow>
     </mrow>
-    <mspace width="2.953em"></mspace>
   </mrow>
 </math>"
 `;
 
 exports[`BussproofsRegProofs Proof Mixing Order 1`] = `
 "<math xmlns="http://www.w3.org/1998/Math/MathML" data-latex="\\begin{prooftree}\\alwaysRootAtTop\\AXC{}\\RL{$Hyp^{1}$}\\UIC{$P$}\\AXC{$P\\rightarrow Q$}\\RL{$\\rightarrow_E$}\\solidLine\\BIC{$Q^2$}\\alwaysRootAtBottom\\AXC{$Q\\rightarrow R$} \\RL{$\\rightarrow_E$} \\BIC{$R$} \\AXC{$Q$}\\RL{Rit$^2$} \\UIC{$Q$}\\RL{$\\wedge_I$}\\BIC{$Q\\wedge R$}\\RL{\${\\rightarrow_I}^1$}\\UIC{$P\\rightarrow Q\\wedge R$}\\end{prooftree}" display="block">
-  <mrow semantics="bspr_inference:1;bspr_proof:true;bspr_labelledRule:right">
-    <mrow>
-      <mspace width="13.25em"></mspace>
-      <mrow data-latex="\\begin{prooftree}\\alwaysRootAtTop\\AXC{}\\RL{$Hyp^{1}$}\\UIC{$P$}\\AXC{$P\\rightarrow Q$}\\RL{$\\rightarrow_E$}\\solidLine\\BIC{$Q^2$}\\alwaysRootAtBottom\\AXC{$Q\\rightarrow R$} \\RL{$\\rightarrow_E$} \\BIC{$R$} \\AXC{$Q$}\\RL{Rit$^2$} \\UIC{$Q$}\\RL{$\\wedge_I$}\\BIC{$Q\\wedge R$}\\RL{\${\\rightarrow_I}^1$}\\UIC{$P\\rightarrow Q\\wedge R$}\\end{prooftree}">
-        <mspace width="-1.155em"></mspace>
+  <mrow style="margin-right: 2.953em" semantics="bspr_inference:1;bspr_proof:true;bspr_labelledRule:right">
+    <mrow style="margin-left: 13.25em">
+      <mrow data-latex="\\begin{prooftree}\\alwaysRootAtTop\\AXC{}\\RL{$Hyp^{1}$}\\UIC{$P$}\\AXC{$P\\rightarrow Q$}\\RL{$\\rightarrow_E$}\\solidLine\\BIC{$Q^2$}\\alwaysRootAtBottom\\AXC{$Q\\rightarrow R$} \\RL{$\\rightarrow_E$} \\BIC{$R$} \\AXC{$Q$}\\RL{Rit$^2$} \\UIC{$Q$}\\RL{$\\wedge_I$}\\BIC{$Q\\wedge R$}\\RL{\${\\rightarrow_I}^1$}\\UIC{$P\\rightarrow Q\\wedge R$}\\end{prooftree}" style="margin-left: -1.155em">
         <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
           <mtr>
             <mtd>
               <mtable framespacing="0 0">
                 <mtr>
                   <mtd rowalign="bottom">
-                    <mrow semantics="bspr_inference:2;bspr_labelledRule:right">
-                      <mrow>
-                        <mspace width="-13.25em"></mspace>
-                        <mrow>
-                          <mspace width="9.111em"></mspace>
+                    <mrow style="margin-right: -5.456em" semantics="bspr_inference:2;bspr_labelledRule:right">
+                      <mrow style="margin-left: -13.25em">
+                        <mrow style="margin-left: 9.111em">
                           <mrow data-latex="\\RL{\${\\rightarrow_I}^1$}">
                             <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
                               <mtr>
@@ -1165,10 +1145,8 @@ exports[`BussproofsRegProofs Proof Mixing Order 1`] = `
                                   <mtable framespacing="0 0">
                                     <mtr>
                                       <mtd rowalign="bottom">
-                                        <mrow semantics="bspr_inference:2;bspr_labelledRule:right">
-                                          <mspace width="-9.111em"></mspace>
-                                          <mrow>
-                                            <mspace width="3.592em"></mspace>
+                                        <mrow style="margin-left: -9.111em" semantics="bspr_inference:2;bspr_labelledRule:right">
+                                          <mrow style="margin-left: 3.592em">
                                             <mrow data-latex="\\BIC{$R$}">
                                               <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
                                                 <mtr>
@@ -1176,8 +1154,7 @@ exports[`BussproofsRegProofs Proof Mixing Order 1`] = `
                                                     <mtable framespacing="0 0">
                                                       <mtr>
                                                         <mtd rowalign="bottom">
-                                                          <mrow semantics="bspr_inference:2;bspr_labelledRule:right">
-                                                            <mspace width="-3.592em"></mspace>
+                                                          <mrow style="margin-left: -3.592em" semantics="bspr_inference:2;bspr_labelledRule:right">
                                                             <mrow data-latex="\\alwaysRootAtBottom">
                                                               <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:up">
                                                                 <mtr>
@@ -1308,7 +1285,7 @@ exports[`BussproofsRegProofs Proof Mixing Order 1`] = `
                                       </mtd>
                                       <mtd></mtd>
                                       <mtd rowalign="bottom">
-                                        <mrow semantics="bspr_inference:1;bspr_labelledRule:right">
+                                        <mrow style="margin-right: -2.055em" semantics="bspr_inference:1;bspr_labelledRule:right">
                                           <mrow data-latex="\\RL{$\\wedge_I$}">
                                             <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
                                               <mtr>
@@ -1352,7 +1329,6 @@ exports[`BussproofsRegProofs Proof Mixing Order 1`] = `
                                               </mstyle>
                                             </mpadded>
                                           </mrow>
-                                          <mspace width="-2.055em"></mspace>
                                         </mrow>
                                       </mtd>
                                     </mtr>
@@ -1384,7 +1360,6 @@ exports[`BussproofsRegProofs Proof Mixing Order 1`] = `
                           </mrow>
                         </mrow>
                       </mrow>
-                      <mspace width="-5.456em"></mspace>
                     </mrow>
                   </mtd>
                 </mtr>
@@ -1424,25 +1399,21 @@ exports[`BussproofsRegProofs Proof Mixing Order 1`] = `
         </mpadded>
       </mrow>
     </mrow>
-    <mspace width="2.953em"></mspace>
   </mrow>
 </math>"
 `;
 
 exports[`BussproofsRegProofs Proof Very Right Label 1`] = `
 "<math xmlns="http://www.w3.org/1998/Math/MathML" data-latex="\\begin{prooftree}\\AxiomC{D}\\AxiomC{A1}\\AxiomC{A2}\\RightLabel{AAAA}\\TrinaryInfC{Q}\\RightLabel{Nowhere}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\RightLabel{BBB}\\BinaryInfC{E}\\RightLabel{CCCCC}\\BinaryInfC{F}\\RightLabel{QERE}\\AxiomC{M}\\UnaryInfC{More and more}\\UnaryInfC{More and more}\\UnaryInfC{More and more}\\BinaryInfC{$N \\rightarrow R$}\\end{prooftree}" display="block">
-  <mrow semantics="bspr_inference:2;bspr_proof:true">
-    <mspace width="9.835em"></mspace>
+  <mrow style="margin-left: 9.835em; margin-right: 3.091em" semantics="bspr_inference:2;bspr_proof:true">
     <mtable align="top 2" rowlines="solid" framespacing="0 0" data-latex="\\begin{prooftree}\\AxiomC{D}\\AxiomC{A1}\\AxiomC{A2}\\RightLabel{AAAA}\\TrinaryInfC{Q}\\RightLabel{Nowhere}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\RightLabel{BBB}\\BinaryInfC{E}\\RightLabel{CCCCC}\\BinaryInfC{F}\\RightLabel{QERE}\\AxiomC{M}\\UnaryInfC{More and more}\\UnaryInfC{More and more}\\UnaryInfC{More and more}\\BinaryInfC{$N \\rightarrow R$}\\end{prooftree}" semantics="bspr_inferenceRule:down">
       <mtr>
         <mtd>
           <mtable framespacing="0 0">
             <mtr>
               <mtd rowalign="bottom">
-                <mrow semantics="bspr_inference:2;bspr_labelledRule:right">
-                  <mspace width="-9.835em"></mspace>
-                  <mrow>
-                    <mspace width="3.274em"></mspace>
+                <mrow style="margin-left: -9.835em" semantics="bspr_inference:2;bspr_labelledRule:right">
+                  <mrow style="margin-left: 3.274em">
                     <mrow data-latex="\\RightLabel{QERE}">
                       <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
                         <mtr>
@@ -1450,8 +1421,7 @@ exports[`BussproofsRegProofs Proof Very Right Label 1`] = `
                             <mtable framespacing="0 0">
                               <mtr>
                                 <mtd rowalign="bottom">
-                                  <mrow semantics="bspr_inference:3;bspr_labelledRule:right">
-                                    <mspace width="-3.274em"></mspace>
+                                  <mrow style="margin-left: -3.274em" semantics="bspr_inference:3;bspr_labelledRule:right">
                                     <mrow data-latex="\\RightLabel{Nowhere}">
                                       <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
                                         <mtr>
@@ -1503,7 +1473,7 @@ exports[`BussproofsRegProofs Proof Very Right Label 1`] = `
                                 </mtd>
                                 <mtd></mtd>
                                 <mtd rowalign="bottom">
-                                  <mrow semantics="bspr_inference:2;bspr_labelledRule:right">
+                                  <mrow style="margin-right: -6.135em" semantics="bspr_inference:2;bspr_labelledRule:right">
                                     <mrow data-latex="\\RightLabel{CCCCC}">
                                       <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
                                         <mtr>
@@ -1519,7 +1489,7 @@ exports[`BussproofsRegProofs Proof Very Right Label 1`] = `
                                                 </mtd>
                                                 <mtd></mtd>
                                                 <mtd rowalign="bottom">
-                                                  <mrow semantics="bspr_inference:2;bspr_labelledRule:right">
+                                                  <mrow style="margin-right: -4.023em" semantics="bspr_inference:2;bspr_labelledRule:right">
                                                     <mrow data-latex="\\RightLabel{BBB}">
                                                       <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
                                                         <mtr>
@@ -1565,7 +1535,6 @@ exports[`BussproofsRegProofs Proof Very Right Label 1`] = `
                                                         <mtext>Nowhere</mtext>
                                                       </mpadded>
                                                     </mrow>
-                                                    <mspace width="-4.023em"></mspace>
                                                   </mrow>
                                                 </mtd>
                                               </mtr>
@@ -1586,7 +1555,6 @@ exports[`BussproofsRegProofs Proof Very Right Label 1`] = `
                                         <mtext>BBB</mtext>
                                       </mpadded>
                                     </mrow>
-                                    <mspace width="-6.135em"></mspace>
                                   </mrow>
                                 </mtd>
                               </mtr>
@@ -1626,7 +1594,7 @@ exports[`BussproofsRegProofs Proof Very Right Label 1`] = `
                                   <mtable framespacing="0 0">
                                     <mtr>
                                       <mtd rowalign="bottom">
-                                        <mrow semantics="bspr_inference:1;bspr_labelledRule:right">
+                                        <mrow style="margin-right: -3.092em" semantics="bspr_inference:1;bspr_labelledRule:right">
                                           <mrow data-latex="\\UnaryInfC{More and more}">
                                             <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
                                               <mtr>
@@ -1658,7 +1626,6 @@ exports[`BussproofsRegProofs Proof Very Right Label 1`] = `
                                               <mtext>QERE</mtext>
                                             </mpadded>
                                           </mrow>
-                                          <mspace width="-3.092em"></mspace>
                                         </mrow>
                                       </mtd>
                                     </mtr>
@@ -1709,14 +1676,13 @@ exports[`BussproofsRegProofs Proof Very Right Label 1`] = `
         </mtd>
       </mtr>
     </mtable>
-    <mspace width="3.091em"></mspace>
   </mrow>
 </math>"
 `;
 
 exports[`BussproofsRegProofs Simple Proof 1`] = `
 "<math xmlns="http://www.w3.org/1998/Math/MathML" data-latex="\\begin{prooftree}\\AxiomC{D}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\BinaryInfC{E}\\BinaryInfC{F}\\end{prooftree}" display="block">
-  <mrow semantics="bspr_inference:2;bspr_proof:true">
+  <mrow style="margin-right: 3.795em" semantics="bspr_inference:2;bspr_proof:true">
     <mtable align="top 2" rowlines="solid" framespacing="0 0" data-latex="\\begin{prooftree}\\AxiomC{D}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\BinaryInfC{E}\\BinaryInfC{F}\\end{prooftree}" semantics="bspr_inferenceRule:down">
       <mtr>
         <mtd>
@@ -1731,7 +1697,7 @@ exports[`BussproofsRegProofs Simple Proof 1`] = `
               </mtd>
               <mtd></mtd>
               <mtd rowalign="bottom">
-                <mrow semantics="bspr_inference:2">
+                <mrow style="margin-right: -3.795em" semantics="bspr_inference:2">
                   <mtable align="top 2" rowlines="solid" framespacing="0 0" data-latex="\\BinaryInfC{E}" semantics="bspr_inferenceRule:down">
                     <mtr>
                       <mtd>
@@ -1801,7 +1767,6 @@ exports[`BussproofsRegProofs Simple Proof 1`] = `
                       </mtd>
                     </mtr>
                   </mtable>
-                  <mspace width="-3.795em"></mspace>
                 </mrow>
               </mtd>
             </mtr>
@@ -1818,31 +1783,27 @@ exports[`BussproofsRegProofs Simple Proof 1`] = `
         </mtd>
       </mtr>
     </mtable>
-    <mspace width="3.795em"></mspace>
   </mrow>
 </math>"
 `;
 
 exports[`BussproofsRegProofs Simple Proof Large 1`] = `
 "<math xmlns="http://www.w3.org/1998/Math/MathML" data-latex="\\begin{prooftree}\\AxiomC{D}\\AxiomC{A1}\\AxiomC{A2}\\TrinaryInfC{Q}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\BinaryInfC{E}\\BinaryInfC{F}\\AxiomC{M}\\BinaryInfC{$N \\rightarrow R$}\\end{prooftree}" display="block">
-  <mrow semantics="bspr_inference:2;bspr_proof:true">
-    <mspace width="8.227em"></mspace>
+  <mrow style="margin-left: 4.953em" semantics="bspr_inference:2;bspr_proof:true">
     <mtable align="top 2" rowlines="solid" framespacing="0 0" data-latex="\\begin{prooftree}\\AxiomC{D}\\AxiomC{A1}\\AxiomC{A2}\\TrinaryInfC{Q}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\BinaryInfC{E}\\BinaryInfC{F}\\AxiomC{M}\\BinaryInfC{$N \\rightarrow R$}\\end{prooftree}" semantics="bspr_inferenceRule:down">
       <mtr>
         <mtd>
           <mtable framespacing="0 0">
             <mtr>
               <mtd rowalign="bottom">
-                <mrow semantics="bspr_inference:2">
-                  <mspace width="-4.953em"></mspace>
+                <mrow style="margin-left: -1.679em" semantics="bspr_inference:2">
                   <mtable align="top 2" rowlines="solid" framespacing="0 0" data-latex="\\BinaryInfC{F}" semantics="bspr_inferenceRule:down">
                     <mtr>
                       <mtd>
                         <mtable framespacing="0 0">
                           <mtr>
                             <mtd rowalign="bottom">
-                              <mrow semantics="bspr_inference:3">
-                                <mspace width="-3.274em"></mspace>
+                              <mrow style="margin-left: -3.274em" semantics="bspr_inference:3">
                                 <mtable align="top 2" rowlines="solid" framespacing="0 0" data-latex="\\TrinaryInfC{Q}" semantics="bspr_inferenceRule:down">
                                   <mtr>
                                     <mtd>
@@ -1889,7 +1850,7 @@ exports[`BussproofsRegProofs Simple Proof Large 1`] = `
                             </mtd>
                             <mtd></mtd>
                             <mtd rowalign="bottom">
-                              <mrow semantics="bspr_inference:2">
+                              <mrow style="margin-right: -3.795em" semantics="bspr_inference:2">
                                 <mtable align="top 2" rowlines="solid" framespacing="0 0" data-latex="\\BinaryInfC{E}" semantics="bspr_inferenceRule:down">
                                   <mtr>
                                     <mtd>
@@ -1959,7 +1920,6 @@ exports[`BussproofsRegProofs Simple Proof Large 1`] = `
                                     </mtd>
                                   </mtr>
                                 </mtable>
-                                <mspace width="-3.795em"></mspace>
                               </mrow>
                             </mtd>
                           </mtr>
@@ -2012,7 +1972,7 @@ exports[`BussproofsRegProofs Simple Proof Large 1`] = `
 
 exports[`BussproofsRegProofs Simple Proof Noise 1`] = `
 "<math xmlns="http://www.w3.org/1998/Math/MathML" data-latex="\\begin{prooftree}\\AxiomC{D}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}$\\alpha$\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\BinaryInfC{E}\\BinaryInfC{F}\\end{prooftree}" display="block">
-  <mrow data-latex="\\begin{prooftree}\\AxiomC{D}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}$\\alpha$\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\BinaryInfC{E}\\BinaryInfC{F}\\end{prooftree}" semantics="bspr_proof:true">
+  <mrow data-latex="\\begin{prooftree}\\AxiomC{D}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}$\\alpha$\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\BinaryInfC{E}\\BinaryInfC{F}\\end{prooftree}" style="margin-right: 3.795em" semantics="bspr_proof:true">
     <mo>$</mo>
     <mi>&#x3B1;</mi>
     <mo>$</mo>
@@ -2030,7 +1990,7 @@ exports[`BussproofsRegProofs Simple Proof Noise 1`] = `
               </mtd>
               <mtd></mtd>
               <mtd rowalign="bottom">
-                <mrow semantics="bspr_inference:2">
+                <mrow style="margin-right: -3.795em" semantics="bspr_inference:2">
                   <mtable align="top 2" rowlines="solid" framespacing="0 0" data-latex="\\BinaryInfC{E}" semantics="bspr_inferenceRule:down">
                     <mtr>
                       <mtd>
@@ -2100,7 +2060,6 @@ exports[`BussproofsRegProofs Simple Proof Noise 1`] = `
                       </mtd>
                     </mtr>
                   </mtable>
-                  <mspace width="-3.795em"></mspace>
                 </mrow>
               </mtd>
             </mtr>
@@ -2117,15 +2076,13 @@ exports[`BussproofsRegProofs Simple Proof Noise 1`] = `
         </mtd>
       </mtr>
     </mtable>
-    <mspace width="3.795em"></mspace>
   </mrow>
 </math>"
 `;
 
 exports[`BussproofsRegProofs Simple Proofs Left Labels 1`] = `
 "<math xmlns="http://www.w3.org/1998/Math/MathML" data-latex="\\begin{prooftree}\\AxiomC{D}\\AxiomC{A1}\\AxiomC{A2}\\TrinaryInfC{Q}\\LeftLabel{AAAA}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\LeftLabel{BBB}\\BinaryInfC{E}\\LeftLabel{CCCCC}\\BinaryInfC{F}\\LeftLabel{QERE}\\AxiomC{M}\\BinaryInfC{$N \\rightarrow R$}\\LeftLabel{Nowhere}\\end{prooftree}" display="block">
-  <mrow semantics="bspr_inference:2;bspr_proof:true;bspr_labelledRule:left">
-    <mspace width="3.835em"></mspace>
+  <mrow style="margin-left: 7.109em" semantics="bspr_inference:2;bspr_proof:true;bspr_labelledRule:left">
     <mrow data-latex="\\begin{prooftree}\\AxiomC{D}\\AxiomC{A1}\\AxiomC{A2}\\TrinaryInfC{Q}\\LeftLabel{AAAA}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\LeftLabel{BBB}\\BinaryInfC{E}\\LeftLabel{CCCCC}\\BinaryInfC{F}\\LeftLabel{QERE}\\AxiomC{M}\\BinaryInfC{$N \\rightarrow R$}\\LeftLabel{Nowhere}\\end{prooftree}">
       <mpadded height=".25em" depth="+.25em" width="+.5ex" voffset="-.25em" semantics="bspr_prooflabel:left">
         <mstyle displaystyle="false">
@@ -2138,12 +2095,9 @@ exports[`BussproofsRegProofs Simple Proofs Left Labels 1`] = `
             <mtable framespacing="0 0">
               <mtr>
                 <mtd rowalign="bottom">
-                  <mrow semantics="bspr_inference:2;bspr_labelledRule:left">
-                    <mspace width="-6.927em"></mspace>
-                    <mrow>
-                      <mspace width="-0.551em"></mspace>
-                      <mrow data-latex="\\LeftLabel{QERE}">
-                        <mspace width="0.551em"></mspace>
+                  <mrow style="margin-left: -10.201em" semantics="bspr_inference:2;bspr_labelledRule:left">
+                    <mrow style="margin-left: -0.551em">
+                      <mrow data-latex="\\LeftLabel{QERE}" style="margin-left: 0.551em">
                         <mpadded height=".25em" depth="+.25em" width="+.5ex" voffset="-.25em" semantics="bspr_prooflabel:left">
                           <mtext>CCCCC</mtext>
                         </mpadded>
@@ -2153,8 +2107,7 @@ exports[`BussproofsRegProofs Simple Proofs Left Labels 1`] = `
                               <mtable framespacing="0 0">
                                 <mtr>
                                   <mtd rowalign="bottom">
-                                    <mrow semantics="bspr_inference:3">
-                                      <mspace width="-3.274em"></mspace>
+                                    <mrow style="margin-left: -3.274em" semantics="bspr_inference:3">
                                       <mtable align="top 2" rowlines="solid" framespacing="0 0" data-latex="\\LeftLabel{AAAA}" semantics="bspr_inferenceRule:down">
                                         <mtr>
                                           <mtd>
@@ -2201,7 +2154,7 @@ exports[`BussproofsRegProofs Simple Proofs Left Labels 1`] = `
                                   </mtd>
                                   <mtd></mtd>
                                   <mtd rowalign="bottom">
-                                    <mrow semantics="bspr_inference:2;bspr_labelledRule:left">
+                                    <mrow style="margin-right: -5.403em" semantics="bspr_inference:2;bspr_labelledRule:left">
                                       <mrow data-latex="\\LeftLabel{CCCCC}">
                                         <mpadded height=".25em" depth="+.25em" width="+.5ex" voffset="-.25em" semantics="bspr_prooflabel:left">
                                           <mtext>BBB</mtext>
@@ -2281,7 +2234,6 @@ exports[`BussproofsRegProofs Simple Proofs Left Labels 1`] = `
                                           </mtr>
                                         </mtable>
                                       </mrow>
-                                      <mspace width="-5.403em"></mspace>
                                     </mrow>
                                   </mtd>
                                 </mtr>
@@ -2337,8 +2289,7 @@ exports[`BussproofsRegProofs Simple Proofs Left Labels 1`] = `
 
 exports[`BussproofsRegProofs Simple Proofs Mixed Labels 1`] = `
 "<math xmlns="http://www.w3.org/1998/Math/MathML" data-latex="\\begin{prooftree}\\AxiomC{D}\\AxiomC{A1}\\AxiomC{A2}\\TrinaryInfC{Q}\\RightLabel{AAAA}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\LeftLabel{BBB}\\BinaryInfC{E}\\LeftLabel{CCCCC}\\BinaryInfC{F}\\RightLabel{QERE}\\LeftLabel{DD}\\AxiomC{M}\\BinaryInfC{$N \\rightarrow R$}\\LeftLabel{Nowhere}\\end{prooftree}" display="block">
-  <mrow semantics="bspr_inference:2;bspr_proof:true;bspr_labelledRule:both">
-    <mspace width="4.379em"></mspace>
+  <mrow style="margin-left: 7.653em" semantics="bspr_inference:2;bspr_proof:true;bspr_labelledRule:both">
     <mrow data-latex="\\begin{prooftree}\\AxiomC{D}\\AxiomC{A1}\\AxiomC{A2}\\TrinaryInfC{Q}\\RightLabel{AAAA}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\LeftLabel{BBB}\\BinaryInfC{E}\\LeftLabel{CCCCC}\\BinaryInfC{F}\\RightLabel{QERE}\\LeftLabel{DD}\\AxiomC{M}\\BinaryInfC{$N \\rightarrow R$}\\LeftLabel{Nowhere}\\end{prooftree}">
       <mpadded height=".25em" depth="+.25em" width="+.5ex" voffset="-.25em" semantics="bspr_prooflabel:left">
         <mstyle displaystyle="false">
@@ -2351,12 +2302,9 @@ exports[`BussproofsRegProofs Simple Proofs Mixed Labels 1`] = `
             <mtable framespacing="0 0">
               <mtr>
                 <mtd rowalign="bottom">
-                  <mrow semantics="bspr_inference:2;bspr_labelledRule:left">
-                    <mspace width="-6.123em"></mspace>
-                    <mrow>
-                      <mspace width="-0.551em"></mspace>
-                      <mrow data-latex="\\LeftLabel{DD}">
-                        <mspace width="0.551em"></mspace>
+                  <mrow style="margin-left: -9.397em" semantics="bspr_inference:2;bspr_labelledRule:left">
+                    <mrow style="margin-left: -0.551em">
+                      <mrow data-latex="\\LeftLabel{DD}" style="margin-left: 0.551em">
                         <mpadded height=".25em" depth="+.25em" width="+.5ex" voffset="-.25em" semantics="bspr_prooflabel:left">
                           <mtext>CCCCC</mtext>
                         </mpadded>
@@ -2366,8 +2314,7 @@ exports[`BussproofsRegProofs Simple Proofs Mixed Labels 1`] = `
                               <mtable framespacing="0 0">
                                 <mtr>
                                   <mtd rowalign="bottom">
-                                    <mrow semantics="bspr_inference:3">
-                                      <mspace width="-3.274em"></mspace>
+                                    <mrow style="margin-left: -3.274em" semantics="bspr_inference:3">
                                       <mtable align="top 2" rowlines="solid" framespacing="0 0" data-latex="\\RightLabel{AAAA}" semantics="bspr_inferenceRule:down">
                                         <mtr>
                                           <mtd>
@@ -2414,7 +2361,7 @@ exports[`BussproofsRegProofs Simple Proofs Mixed Labels 1`] = `
                                   </mtd>
                                   <mtd></mtd>
                                   <mtd rowalign="bottom">
-                                    <mrow semantics="bspr_inference:2;bspr_labelledRule:left">
+                                    <mrow style="margin-right: -3.795em" semantics="bspr_inference:2;bspr_labelledRule:left">
                                       <mrow data-latex="\\LeftLabel{CCCCC}">
                                         <mpadded height=".25em" depth="+.25em" width="+.5ex" voffset="-.25em" semantics="bspr_prooflabel:left">
                                           <mtext>BBB</mtext>
@@ -2433,7 +2380,7 @@ exports[`BussproofsRegProofs Simple Proofs Mixed Labels 1`] = `
                                                   </mtd>
                                                   <mtd></mtd>
                                                   <mtd rowalign="bottom">
-                                                    <mrow semantics="bspr_inference:2;bspr_labelledRule:right">
+                                                    <mrow style="margin-right: -3.216em" semantics="bspr_inference:2;bspr_labelledRule:right">
                                                       <mrow data-latex="\\LeftLabel{BBB}">
                                                         <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
                                                           <mtr>
@@ -2479,7 +2426,6 @@ exports[`BussproofsRegProofs Simple Proofs Mixed Labels 1`] = `
                                                           <mtext>AAAA</mtext>
                                                         </mpadded>
                                                       </mrow>
-                                                      <mspace width="-3.216em"></mspace>
                                                     </mrow>
                                                   </mtd>
                                                 </mtr>
@@ -2497,7 +2443,6 @@ exports[`BussproofsRegProofs Simple Proofs Mixed Labels 1`] = `
                                           </mtr>
                                         </mtable>
                                       </mrow>
-                                      <mspace width="-3.795em"></mspace>
                                     </mrow>
                                   </mtd>
                                 </mtr>
@@ -2558,8 +2503,7 @@ exports[`BussproofsRegProofs Simple Proofs Mixed Labels 1`] = `
 
 exports[`BussproofsRegProofs Simple Proofs Right Labels 1`] = `
 "<math xmlns="http://www.w3.org/1998/Math/MathML" data-latex="\\begin{prooftree}\\AxiomC{D}\\AxiomC{A1}\\AxiomC{A2}\\TrinaryInfC{Q}\\RightLabel{AAAA}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\RightLabel{BBB}\\BinaryInfC{E}\\RightLabel{CCCCC}\\BinaryInfC{F}\\RightLabel{QERE}\\AxiomC{M}\\BinaryInfC{$N \\rightarrow R$}\\RightLabel{Nowhere}\\end{prooftree}" display="block">
-  <mrow semantics="bspr_inference:2;bspr_proof:true;bspr_labelledRule:right">
-    <mspace width="8.227em"></mspace>
+  <mrow style="margin-left: 8.227em" semantics="bspr_inference:2;bspr_proof:true;bspr_labelledRule:right">
     <mrow data-latex="\\begin{prooftree}\\AxiomC{D}\\AxiomC{A1}\\AxiomC{A2}\\TrinaryInfC{Q}\\RightLabel{AAAA}\\AxiomC{A}\\AxiomC{B}\\AxiomC{R}\\BinaryInfC{$C \\rightarrow D \\rightarrow Q$}\\RightLabel{BBB}\\BinaryInfC{E}\\RightLabel{CCCCC}\\BinaryInfC{F}\\RightLabel{QERE}\\AxiomC{M}\\BinaryInfC{$N \\rightarrow R$}\\RightLabel{Nowhere}\\end{prooftree}">
       <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
         <mtr>
@@ -2567,10 +2511,8 @@ exports[`BussproofsRegProofs Simple Proofs Right Labels 1`] = `
             <mtable framespacing="0 0">
               <mtr>
                 <mtd rowalign="bottom">
-                  <mrow semantics="bspr_inference:2;bspr_labelledRule:right">
-                    <mspace width="-8.227em"></mspace>
-                    <mrow>
-                      <mspace width="3.274em"></mspace>
+                  <mrow style="margin-left: -8.227em" semantics="bspr_inference:2;bspr_labelledRule:right">
+                    <mrow style="margin-left: 3.274em">
                       <mrow data-latex="\\RightLabel{QERE}">
                         <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
                           <mtr>
@@ -2578,8 +2520,7 @@ exports[`BussproofsRegProofs Simple Proofs Right Labels 1`] = `
                               <mtable framespacing="0 0">
                                 <mtr>
                                   <mtd rowalign="bottom">
-                                    <mrow semantics="bspr_inference:3">
-                                      <mspace width="-3.274em"></mspace>
+                                    <mrow style="margin-left: -3.274em" semantics="bspr_inference:3">
                                       <mtable align="top 2" rowlines="solid" framespacing="0 0" data-latex="\\RightLabel{AAAA}" semantics="bspr_inferenceRule:down">
                                         <mtr>
                                           <mtd>
@@ -2626,7 +2567,7 @@ exports[`BussproofsRegProofs Simple Proofs Right Labels 1`] = `
                                   </mtd>
                                   <mtd></mtd>
                                   <mtd rowalign="bottom">
-                                    <mrow semantics="bspr_inference:2;bspr_labelledRule:right">
+                                    <mrow style="margin-right: -6.134em" semantics="bspr_inference:2;bspr_labelledRule:right">
                                       <mrow data-latex="\\RightLabel{CCCCC}">
                                         <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
                                           <mtr>
@@ -2642,7 +2583,7 @@ exports[`BussproofsRegProofs Simple Proofs Right Labels 1`] = `
                                                   </mtd>
                                                   <mtd></mtd>
                                                   <mtd rowalign="bottom">
-                                                    <mrow semantics="bspr_inference:2;bspr_labelledRule:right">
+                                                    <mrow style="margin-right: -3.216em" semantics="bspr_inference:2;bspr_labelledRule:right">
                                                       <mrow data-latex="\\RightLabel{BBB}">
                                                         <mtable align="top 2" rowlines="solid" framespacing="0 0" semantics="bspr_inferenceRule:down">
                                                           <mtr>
@@ -2688,7 +2629,6 @@ exports[`BussproofsRegProofs Simple Proofs Right Labels 1`] = `
                                                           <mtext>AAAA</mtext>
                                                         </mpadded>
                                                       </mrow>
-                                                      <mspace width="-3.216em"></mspace>
                                                     </mrow>
                                                   </mtd>
                                                 </mtr>
@@ -2709,7 +2649,6 @@ exports[`BussproofsRegProofs Simple Proofs Right Labels 1`] = `
                                           <mtext>BBB</mtext>
                                         </mpadded>
                                       </mrow>
-                                      <mspace width="-6.134em"></mspace>
                                     </mrow>
                                   </mtd>
                                 </mtr>
diff --git a/ts/input/tex/bussproofs/BussproofsUtil.ts b/ts/input/tex/bussproofs/BussproofsUtil.ts
index 3e1caccc6..514200d87 100644
--- a/ts/input/tex/bussproofs/BussproofsUtil.ts
+++ b/ts/input/tex/bussproofs/BussproofsUtil.ts
@@ -52,7 +52,7 @@ let item: MATHITEM = null;
  * @param {MmlNode} node The target node.
  * @returns {number} Width of the proof node.
  */
-const getBBox = function (node: MmlNode) {
+const getBBox = function (node: MmlNode): number {
   item.root = node;
   const { w: width } = (doc.outputJax as any).getBBox(item, doc);
   return width;
@@ -190,8 +190,8 @@ const getParentInf = function (inf: MmlNode): MmlNode {
   return inf;
 };
 
-// Computes bbox spaces
 //
+// Computes bbox spaces
 //
 
 /**
@@ -214,6 +214,8 @@ const getSpaces = function (
     return result;
   }
   if (inf !== rule.parent) {
+    result +=
+      (inf.getProperty(right ? 'proof-right' : 'proof-left') as number) || 0;
     const children = inf.childNodes;
     const index = right ? children.length - 1 : 0;
     if (NodeUtil.isType(children[index], 'mspace')) {
@@ -278,29 +280,16 @@ const addSpace = function (
     moveProperties(inf, mrow);
     inf = mrow;
   }
-  // TODO: Simplify below as we now have a definite mrow.
-  const index = right ? inf.childNodes.length - 1 : 0;
-  let mspace = inf.childNodes[index];
-  if (NodeUtil.isType(mspace, 'mspace')) {
-    NodeUtil.setAttribute(
-      mspace,
-      'width',
-      UnitUtil.em(
-        UnitUtil.dimen2em(NodeUtil.getAttribute(mspace, 'width') as string) +
-          space
-      )
-    );
-    return;
-  }
-  mspace = config.nodeFactory.create('node', 'mspace', [], {
-    width: UnitUtil.em(space),
-  });
-  if (right) {
-    inf.appendChild(mspace);
-    return;
+  const prop = right ? 'proof-right' : 'proof-left';
+  inf.setProperty(prop, ((inf.getProperty(prop) as number) || 0) + space);
+  const styles = [];
+  for (const side of ['left', 'right']) {
+    const margin = inf.getProperty(`proof-${side}`) as number;
+    if (margin) {
+      styles.push(`margin-${side}: ${UnitUtil.em(margin)}`);
+    }
   }
-  mspace.parent = inf;
-  inf.childNodes.unshift(mspace);
+  inf.attributes.set('style', styles.join('; '));
 };
 
 /**

From ab4dbad4821cfe1b261121559c3f1e1b2f7eabd5 Mon Sep 17 00:00:00 2001
From: "Davide P. Cervone" <dpvc@union.edu>
Date: Thu, 9 Apr 2026 08:13:02 -0400
Subject: [PATCH 2/2] Remove unneeded check for mspace since they are no longer
 used

---
 ts/input/tex/bussproofs/BussproofsUtil.ts | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/ts/input/tex/bussproofs/BussproofsUtil.ts b/ts/input/tex/bussproofs/BussproofsUtil.ts
index 514200d87..a69d5f0c6 100644
--- a/ts/input/tex/bussproofs/BussproofsUtil.ts
+++ b/ts/input/tex/bussproofs/BussproofsUtil.ts
@@ -216,11 +216,6 @@ const getSpaces = function (
   if (inf !== rule.parent) {
     result +=
       (inf.getProperty(right ? 'proof-right' : 'proof-left') as number) || 0;
-    const children = inf.childNodes;
-    const index = right ? children.length - 1 : 0;
-    if (NodeUtil.isType(children[index], 'mspace')) {
-      result += getBBox(children[index]);
-    }
     inf = rule.parent;
   }
   if (inf === rule) {