assign-such-that-antecedent.dfy(8,8): Error: cannot establish the existence of LHS values that satisfy the such-that predicate
Execution trace:
    (0,0): anon0
    (0,0): anon3_Then
    (0,0): anon2
assign-such-that-antecedent.dfy(13,9): Error: assertion violation
Execution trace:
    (0,0): anon0
    (0,0): anon4_Then
    (0,0): anon5_Then
    (0,0): anon3

Dafny program verifier finished with 2 verified, 2 errors
