Datasets:
File size: 906 Bytes
c62beea | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 | use vstd::prelude::*;
fn main() {}
verus!{
spec fn f1_sum_negative_to(seq: Seq<i64>) -> int
decreases seq.len(),
{
if seq.len() == 0 {
0
} else {
f1_sum_negative_to(seq.drop_last()) + if (seq.last() < 0) {
seq.last() as int
} else {
0 as int
}
}
}
fn f1_sum_negatives(arr: &Vec<i64>) -> (sum_neg: i128)
{
let mut index = 0;
let mut sum_neg = 0i128;
while index < arr.len()
{
if (arr[index] < 0) {
sum_neg = sum_neg + (arr[index] as i128);
}
index += 1;
}
sum_neg
}
spec fn step1(__hp0: Seq<i64>, outp: i128) -> bool {
(f1_sum_negative_to(__hp0) == outp)
}
fn chain_driver(arr: &Vec<i64>) -> (r_final: i128)
ensures
step1(arr@, r_final),
{
let x1 = f1_sum_negatives(arr);
proof {
assert(step1(arr@, x1));
}
x1
}
} // verus!
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