The "choose" statement, hacky and specialized as it was, is now gone. Use the assign-such-that statement instead. For example: x :| x in S;

1 files changed, 5 insertions, 5 deletions

diff --git a/Test/dafny1/Celebrity.dfy b/Test/dafny1/Celebrity.dfy
index 4c761671..a4043f4d 100644
--- a/Test/dafny1/Celebrity.dfy
+++ b/Test/dafny1/Celebrity.dfy
@@ -22,20 +22,20 @@ method FindCelebrity1<Person>(people: set<Person>, ghost c: Person) returns (r:
   ensures r == c;

 {

   var Q := people;

-  var x := choose Q;

+  var x :| x in Q;

   while (Q != {x})

     //invariant Q <= people;  // inv1 in Rodin's Celebrity_1, but it's not needed here

     invariant IsCelebrity(c, Q);  // inv2

     invariant x in Q;

     decreases Q;

   {

-    var y := choose Q - {x};

+    var y :| y in Q - {x};

     if (Knows(x, y)) {

       Q := Q - {x};  // remove_1

     } else {

       Q := Q - {y};  assert x in Q;  // remove_2

     }

-    x := choose Q;

+    x :| x in Q;

   }

   r := x;

 }

@@ -44,7 +44,7 @@ method FindCelebrity2<Person>(people: set<Person>, ghost c: Person) returns (r:
   requires IsCelebrity(c, people);

   ensures r == c;

 {

-  var b := choose people;

+  var b :| b in people;

   var R := people - {b};

   while (R != {})

     invariant R <= people;  // inv1

@@ -54,7 +54,7 @@ method FindCelebrity2<Person>(people: set<Person>, ghost c: Person) returns (r:
 

     decreases R;

   {

-    var x := choose R;

+    var x :| x in R;

     if (Knows(x, b)) {

       R := R - {x};

     } else {