Lambda.dfy(24,11): Error: assertion violation
Execution trace:
    (0,0): anon0
    Lambda.dfy(6,24): anon31_Else
    Lambda.dfy(7,24): anon32_Else
    Lambda.dfy(8,26): anon33_Else
    Lambda.dfy(10,34): anon34_Else
    Lambda.dfy(11,15): anon35_Else
    Lambda.dfy(13,15): anon36_Else
    Lambda.dfy(14,15): anon39_Else
    Lambda.dfy(18,15): anon42_Else
    Lambda.dfy(23,15): anon44_Else

Dafny program verifier finished with 7 verified, 1 error