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-rw-r--r--Chalice/tests/refinements/experiments/DSW1.chalice91
1 files changed, 0 insertions, 91 deletions
diff --git a/Chalice/tests/refinements/experiments/DSW1.chalice b/Chalice/tests/refinements/experiments/DSW1.chalice
deleted file mode 100644
index 612f21ac..00000000
--- a/Chalice/tests/refinements/experiments/DSW1.chalice
+++ /dev/null
@@ -1,91 +0,0 @@
-// Schorr-Waite algorithm in Chalice
-// (see Test/dafny1/SchorrWaite.dfy)
-
-// Arbitrary number of children
-// No counter for visited nodes; next node is selected non-deterministically
-class Node {
- var children: seq<Node>;
- var marked: bool;
- ghost var path: seq<Node>;
-}
-
-class Main {
- function Reachable(to: Node, p:seq<Node>, from: Node): bool
- requires acc(p[*].children);
- {
- |p| == 0 ? to == from :
- (p[0] != null && to in p[0].children && Reachable(p[0], p[1..], from))
- }
-
- method IterativeMark(root: Node, S: seq<Node>)
- requires acc(S[*].*);
- requires root in S;
- requires forall n in S :: n != null && (forall ch in n.children :: ch != null && ch in S);
- requires forall n in S :: ! n.marked;
- ensures acc(S[*].*);
- // graph structure is the same
- ensures forall n in S :: n.children == old(n.children);
- // all nodes reachable from root are marked
- ensures root.marked;
- ensures forall n in S :: n.marked ==> (forall ch in n.children :: ch.marked);
- // all marked nodes are reachable from root
- ensures forall n in S :: n.marked ==>
- (forall m in n.path :: m in S) && Reachable(n, n.path, root);
- {
- var t:Node := root;
- t.marked := true;
- var stack: seq<Node> := [];
- t.path := stack;
-
- // no termination check
- var stop := false;
- while(!stop)
- invariant acc(S[*].*);
- invariant root.marked;
- invariant t in S && t.marked && t !in stack;
- // stack well-formed
- invariant forall i in [0..|stack|] :: forall j in [i+1..|stack|] :: stack[i] != stack[j];
- invariant forall n in stack :: n in S && n.marked;
- invariant forall i in [1..|stack|] :: stack[i-1] in stack[i].children;
- invariant 0 < |stack| ==> t in stack[0].children;
- // goal
- invariant forall n in S :: n.marked && n !in stack && n != t ==>
- (forall ch in n.children :: ch in S && ch.marked);
- invariant forall n in S :: n.marked ==>
- (forall m in n.path :: m in S) && Reachable(n, n.path, root);
- // preservation
- invariant forall n in S :: n.children == old(n.children);
- // termination
- invariant stop ==> |stack| == 0 && (forall ch in t.children :: ch.marked);
- {
- call n := PickUnmarked(t.children);
-
- if (n != null) {
- // push
- stack := [t] ++ stack;
- n.path := [t] ++ t.path;
- t := n;
- t.marked := true;
- assert Reachable(t.path[0], t.path[1..], root); // needed for limited function
- } else {
- // pop
- if (|stack| == 0) {
- stop := true;
- } else {
- t := stack[0];
- stack := stack[1..];
- }
- }
- }
- }
-
- method PickUnmarked(p: seq<Node>) returns (x: Node)
- requires rd(p[*].marked);
- requires forall n in p :: n != null;
- ensures rd(p[*].marked);
- ensures x != null ==> x in p && ! x.marked;
- ensures x == null ==> (forall n in p :: n.marked);
- {
- assume false; // magic!
- }
-}