Char.dfy(48,20): Error: assertion might not hold
Char.dfy(52,20): Error: assertion might not hold
Char.dfy(63,16): Error: assertion might not hold
Char.dfy(81,7): Error: char subtraction might underflow
Char.dfy(81,13): Error: char addition might overflow
Char.dfy(89,7): Error: char subtraction might underflow
Char.dfy(97,13): Error: char addition might overflow
Char.dfy(105,7): Error: char subtraction might underflow

Dafny program verifier finished with 8 verified, 8 errors
