parsing prefix version (binary operators) of msph

example/ex3.msph

@@ -0,0 +1,13 @@
+
+type X = & C (| D E)
+
+type Y = {
+	member x : X
+	type Z = & X {
+ 		type T = C
+		assert C <: D
+	}
+	member r : (box forall S. (=> S Y))
+	member s : C[X, Y, z]
+	member f : -> A B
+}