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// RUN: %dafny /compile:0 /print:"%t.print" /dprint:"%t.dprint" "%s" > "%t"
// RUN: %diff "%s.expect" "%t"
ghost method M(n: nat) //returns (y: nat)
{
var y := F(n, 0);
}
function F(n: nat, p: int): nat
{
calc {
100;
< { if n != 0 { M(n-1); } }
102;
}
n
}
ghost method MM(n: nat) returns (y: nat)
decreases n, 0;
{
if n != 0 {
y := FF(n-1);
}
}
function FF(n: nat): nat
decreases n, 1;
{
calc {
100;
< { var y := MM(n); }
102;
}
n
}
ghost method P(n: nat)
{
if n != 0 {
var y :=
calc {
12;
{ P(n-1); }
12;
}
100;
assert y == 100;
}
}
ghost method Q(n: nat)
{
if n != 0 {
var y :=
calc {
12;
{ Q(n+1); } // error: cannot prove termination
12;
}
100;
assert y == 102; // error: assertion does not hold
}
}
// ---------------------
function Fact(n: nat): nat
{
if n == 0 then 1 else n * Fact(n-1)
}
lemma L(n: nat)
ensures 1 <= Fact(n);
{
}
function F_Fails(n: nat): int
{
50 / Fact(n) // error: possible division by zero
}
function F_Succeeds(n: nat): int
{
L(n);
50 / Fact(n)
}
function F_PreconditionViolation(n: int): int
{
L(n); // error: argument might be negative
50 / Fact(n)
}
// --------------------- These had had parsing problems in the past
lemma MyLemma(x: int) {
var d: Dtz;
if 0 < x {
var y: int;
match MyLemma(y); d { // error: cannot prove termination
case Cons0(_) =>
case Cons1(_) =>
}
}
}
function Parsing_Regression_test0(): int
{
var x := 12;
assert x < 20;
MyLemma(x);
calc { x; < x+1; }
// and again
var x := 12;
assert x < 20;
MyLemma(x);
calc { x; < x+1; }
17
}
datatype Dtz = Cons0(int) | Cons1(bool)
function Parsing_Regression_test1(dtz: Dtz): int
{
match dtz
case Cons0(s) =>
var x := 12;
assert x < 20;
MyLemma(x);
calc { x; < x+1; }
// and again
var x := 12;
assert x < 20;
MyLemma(x);
calc { x; < x+1; }
17
case Cons1(_) =>
var x := 12;
assert x < 20;
MyLemma(x);
calc { x; < x+1; }
// and again
var x := 12;
assert x < 20;
MyLemma(x);
calc { x; < x+1; }
19
}
function Parsing_Regression_test2(): int
{
// parentheses should be allowed anywhere
var x := 12;
( assert x < 20;
( MyLemma(x);
( calc { x; < x+1; }
( var x := 12;
( assert x < 20;
( MyLemma(x);
( calc { x; < x+1; }
17
) ) ) ) ) ) )
}
|
