Make sure that RealInfix.(-.) unfolds to Real.(-).

lib/coq/real/RealInfix.v

@@ -15,10 +15,3 @@ Require Import BuiltIn.
 Require BuiltIn.
 Require real.Real.
 
-(* Why3 goal *)
-Lemma infix_mndt_def : forall (x:R) (y:R), ((x - y)%R = (x + (-y)%R)%R).
-Proof.
-intros x y.
-reflexivity.
-Qed.
-

lib/isabelle/realizations.2018

@@ -7,7 +7,7 @@ f93d912698cd9b10846cd861492655f1c6cf9ab0  int/MinMax.xml
 9e550b757adffdb78db010e8aa14b85a065b3c60  int/Power.xml
 79ca42a9fba90deb0e8eb7fb5396de8a756ac969  bool/Bool.xml
 6bb79ae3bc3abb9b0710a2dfd58c0bd2c41b8f13  real/Real.xml
-657f5992027dc0d739351289093cac512a534fcb  real/RealInfix.xml
+f80da4609433de4d5ccb6ebbbe0fa954c5ed5187  real/RealInfix.xml
 c2410d334c7e0852086bb13cae1189f601f3b1c6  real/Abs.xml
 da70a842eac8ff6687f1d119c309be4c227976ff  real/MinMax.xml
 3cc6bd97503e596fae70c51ef1d5401a62114b94  real/FromInt.xml

stdlib/real.mlw

@@ -20,7 +20,6 @@ module Real
   val function  (*)  real real : real
   val predicate (<)  real real : bool
 
-  let (-)  (x y : real) = x + -y
   let predicate (>)  (x y : real) = y < x
   let predicate (<=) (x y : real) = x < y || x = y
   let predicate (>=) (x y : real) = y <= x
@@ -30,6 +29,10 @@ module Real
     function (-_) = (-_), function (+) = (+),
     function (*) = (*), predicate (<=) = (<=)
 
+  let (-) (x y : real)
+    ensures { result = x - y }
+  = x + -y
+
   val (/) (x y:real) : real
     requires { y <> 0.0 }
     ensures  { result = x / y }