Support nested Condition.

examples/test_rubi.m

@@ -0,0 +1,14 @@
+testproblems = ReadList["/Users/cwalker32/Code/gocode/src/github.com/corywalker/expreduce/test_rubi/test_rubi.m"];
+testproblems = DeleteCases[testproblems, Null];
+
+testi = 1;
+
+While[testi <= Length[testproblems],
+    testp = testproblems[[testi]];
+    (*Print[testp];*)
+    res = Int[testp[[1]], testp[[2]]];
+    (*Print[res];*)
+    (*Print[res === testp[[4]]];*)
+    If[res === testp[[4]], Print[testi]];
+    testi = testi+1;
+];

expreduce/replace.go

@@ -102,19 +102,31 @@ func ReplaceAll(this Ex, r *Expression, es *EvalState, pm *PDManager,
 	return this
 }
 
+func tryCondWithMatches(asCond *Expression, matches *PDManager, es *EvalState) (Ex, bool) {
+	condRes := ReplacePD(asCond.Parts[2], es, matches).Eval(es)
+	condResSymbol, condResIsSymbol := condRes.(*Symbol)
+	if condResIsSymbol {
+		if condResSymbol.Name == "System`True" {
+			toReturn := ReplacePD(asCond.Parts[1], es, matches)
+			if rCond, isRCond := HeadAssertion(toReturn, "System`Condition"); isRCond {
+				return tryCondWithMatches(rCond, matches, es)
+			}
+			return toReturn, true
+		}
+	}
+	return nil, false
+}
+
 func Replace(this Ex, r *Expression, es *EvalState) (Ex, bool) {
 	if asCond, isCond := HeadAssertion(r.Parts[2], "System`Condition"); isCond {
 		mi, cont := NewMatchIter(this, r.Parts[1], EmptyPD(), es)
 		for cont {
 			res, matches, done := mi.next()
 			cont = !done
 			if res {
-				condRes := ReplacePD(asCond.Parts[2], es, matches).Eval(es)
-				condResSymbol, condResIsSymbol := condRes.(*Symbol)
-				if condResIsSymbol {
-					if condResSymbol.Name == "System`True" {
-						return ReplacePD(asCond.Parts[1], es, matches), true
-					}
+				toReturn, ok := tryCondWithMatches(asCond, matches, es)
+				if ok {
+					return toReturn, true
 				}
 			}
 		}