1 files changed, 2 insertions, 2 deletions
diff --git a/typing.cpp b/typing.cpp
index cfc1104..0e63f26 100644
--- a/typing.cpp
+++ b/typing.cpp
@@ -252,11 +252,11 @@ Subst::compose(const Subst& delta, const Subst& gamma) // TAPL 22.1.1
 	Subst r;
 	for (Subst::const_iterator g = gamma.begin(); g != gamma.end(); ++g) {
 		Subst::const_iterator d = delta.find(g->second);
-		r.insert(make_pair(g->first, ((d != delta.end()) ? d : g)->second));
+		r.add(g->first, ((d != delta.end()) ? d : g)->second);
 	}
 	for (Subst::const_iterator d = delta.begin(); d != delta.end(); ++d) {
 		if (gamma.find(d->first) == gamma.end())
-			r.insert(*d);
+			r.add(d->first, d->second);
 	}
 	return r;
 }