Add Fractional instance for Expr.

diff --git a/LTA/Symbolic.hs b/LTA/Symbolic.hs
index a46846a9d34647d9b2ce0a1abd9d6598baea8273..f29070fa6f7dd504c34414437f4046e112d1857f 100644 (file)
--- a/LTA/Symbolic.hs
+++ b/LTA/Symbolic.hs
@@ -184,3 +184,7 @@ instance Num Expr where
   fromInteger = Literal . fromInteger
   negate a = simplify $ Sum $ empty `addPair` (a, -1)
   signum = UnaryFunction Signum
+
+instance Fractional Expr where
+  (/) a b = simplify $ Product $ empty `addPair` (a, 1) `addPair` (b, -1)
+  fromRational = Literal . RationalLiteral