sqrtProduct and sqrtDivision rules use agc flags

This allows them to match them up to associativity and commutativity,
and with other subexpressions in-between.

Author: christianp

runtime/scripts/jme-rules.js

@@ -2107,10 +2107,10 @@ var simplificationRules = jme.rules.simplificationRules = {
         ['(`! `+- $n);x * (real:$n/real:$n`?);n','asg','n*x']
     ],
     sqrtProduct: [
-        ['sqrt(?;x)*sqrt(?;y)','','sqrt(x*y)']
+        ['sqrt(?;x)*sqrt(?;y)','agc','sqrt(x*y)']
     ],
     sqrtDivision: [
-        ['sqrt(?;x)/sqrt(?;y)','','sqrt(x/y)']
+        ['sqrt(?;x)/sqrt(?;y)','agc','sqrt(x/y)']
     ],
     sqrtSquare: [
         ['sqrt(?;x^2)','','x'],

tests/jme-runtime.js

@@ -8650,10 +8650,10 @@ var simplificationRules = jme.rules.simplificationRules = {
         ['(`! `+- $n);x * (real:$n/real:$n`?);n','asg','n*x']
     ],
     sqrtProduct: [
-        ['sqrt(?;x)*sqrt(?;y)','','sqrt(x*y)']
+        ['sqrt(?;x)*sqrt(?;y)','agc','sqrt(x*y)']
     ],
     sqrtDivision: [
-        ['sqrt(?;x)/sqrt(?;y)','','sqrt(x/y)']
+        ['sqrt(?;x)/sqrt(?;y)','agc','sqrt(x/y)']
     ],
     sqrtSquare: [
         ['sqrt(?;x^2)','','x'],

tests/jme/jme-tests.mjs

@@ -2223,6 +2223,16 @@ Numbas.queueScript('jme_tests',['qunit','jme','jme-rules','jme-display','jme-cal
         assert.equal(simplifyExpression('a/(b/c*d)', 'all'), 'a*c/(b*d)', 'a/(b/c*d)');
     });
 
+    QUnit.test('Simplify surds', function(assert) {
+        function simplifyExpression(expr,rules) {
+            return Numbas.jme.display.simplifyExpression(expr,rules || '',Numbas.jme.builtinScope);
+        }
+
+        assert.equal(simplifyExpression('sqrt(a)*x*sqrt(b)','all'), 'sqrt(a*b)*x');
+        assert.equal(simplifyExpression('sqrt(a)*(x*sqrt(b))','all'), 'sqrt(a*b)*x');
+        assert.equal(simplifyExpression('x/sqrt(a)*sqrt(b)','all'), 'x*sqrt(b/a)');
+    });
+
     QUnit.test('brackets involving subtraction', function(assert) {
         function simplifyExpression(expr,rules) {
             return Numbas.jme.display.simplifyExpression(expr,rules || '',Numbas.jme.builtinScope);

tests/numbas-runtime.js

@@ -7986,10 +7986,10 @@ var simplificationRules = jme.rules.simplificationRules = {
         ['(`! `+- $n);x * (real:$n/real:$n`?);n','asg','n*x']
     ],
     sqrtProduct: [
-        ['sqrt(?;x)*sqrt(?;y)','','sqrt(x*y)']
+        ['sqrt(?;x)*sqrt(?;y)','agc','sqrt(x*y)']
     ],
     sqrtDivision: [
-        ['sqrt(?;x)/sqrt(?;y)','','sqrt(x/y)']
+        ['sqrt(?;x)/sqrt(?;y)','agc','sqrt(x/y)']
     ],
     sqrtSquare: [
         ['sqrt(?;x^2)','','x'],