original.name="Quantifiers_Valid_1"
======
>>> main.whiley
function f(int[] xs) -> int[]
requires all { i in 0..|xs| | xs[i] >= 0 }:
return xs
public export method test() :
int[] ys = [1, 2, 3]
int[] zs = ys
assume f(zs) == [1,2,3]
assert ys == [1,2,3]
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