diff --git a/src/commands/math/commands.js b/src/commands/math/commands.js
index fdd3cf2..de5c53b 100644
--- a/src/commands/math/commands.js
+++ b/src/commands/math/commands.js
@@ -563,11 +563,9 @@
   _.latex = function() {
     return '\\left'+this.sides[L].ctrlSeq+this.ends[L].latex()+'\\right'+this.sides[R].ctrlSeq;
   };
-  _.oppBrack = function(opts, node, expectedSide) {
-    // return node iff it's a 1-sided bracket of expected side (if any, may be
-    // undefined), and of opposite side from me if I'm not a pipe
+  _.matchBrack = function(opts, expectedSide, node) {
+    // return node iff it's a matching 1-sided bracket of expected side (if any)
     return node instanceof Bracket && node.side && node.side !== -expectedSide
-      && (this.sides[this.side].ch === '|' || node.side === -this.side)
       && (!opts.restrictMismatchedBrackets
         || OPP_BRACKS[this.sides[this.side].ch] === node.sides[node.side].ch
         || { '(': ']', '[': ')' }[this.sides[L].ch] === node.sides[R].ch) && node;
@@ -581,11 +579,16 @@
   _.createLeftOf = function(cursor) {
     if (!this.replacedFragment) { // unless wrapping seln in brackets,
         // check if next to or inside an opposing one-sided bracket
-        // (must check both sides 'cos I might be a pipe)
       var opts = cursor.options;
-      var brack = this.oppBrack(opts, cursor[L], L)
-                  || this.oppBrack(opts, cursor[R], R)
-                  || this.oppBrack(opts, cursor.parent.parent);
+      if (this.sides[L].ch === '|') { // check both sides if I'm a pipe
+        var brack = this.matchBrack(opts, R, cursor[R])
+                 || this.matchBrack(opts, L, cursor[L])
+                 || this.matchBrack(opts, 0, cursor.parent.parent);
+      }
+      else {
+        var brack = this.matchBrack(opts, -this.side, cursor[-this.side])
+                 || this.matchBrack(opts, -this.side, cursor.parent.parent);
+      }
     }
     if (brack) {
       var side = this.side = -brack.side; // may be pipe with .side not yet set
@@ -627,7 +630,7 @@
     var opts = cursor.options, wasSolid = !this.side;
     this.side = -side;
     // if deleting like, outer close-brace of [(1+2)+3} where inner open-paren
-    if (this.oppBrack(opts, this.ends[L].ends[this.side], side)) { // is ghost,
+    if (this.matchBrack(opts, side, this.ends[L].ends[this.side])) { // is ghost,
       this.closeOpposing(this.ends[L].ends[this.side]); // then become [1+2)+3
       var origEnd = this.ends[L].ends[side];
       this.unwrap();
@@ -635,7 +638,7 @@
       sib ? cursor.insDirOf(-side, sib) : cursor.insAtDirEnd(side, parent);
     }
     else { // if deleting like, inner close-brace of ([1+2}+3) where outer
-      if (this.oppBrack(opts, this.parent.parent, side)) { // open-paren is
+      if (this.matchBrack(opts, side, this.parent.parent)) { // open-paren is
         this.parent.parent.closeOpposing(this); // ghost, then become [1+2+3)
         this.parent.parent.unwrap();
       } // else if deleting outward from a solid pair, unwrap