From: Francis Russell <francis@unchartedbackwaters.co.uk>
Date: Fri, 12 Apr 2013 15:40:20 +0000 (+0100)
Subject: Add Fractional instance for Expr.
X-Git-Url: https://git.unchartedbackwaters.co.uk/w/?a=commitdiff_plain;h=0cfdbb7ab4de0a2b1d5731305b14617c46c27222;p=francis%2Flta.git

Add Fractional instance for Expr.
---

diff --git a/LTA/Symbolic.hs b/LTA/Symbolic.hs
index a46846a..f29070f 100644
--- 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