⊦ ¬ j < 0 → abs(j) = j
¬ ¬ dec.int < 0 ⊦ mkDecimal(abs(dec.int), dec.scale).int = abs(dec.int)
¬ dec.int < 0 ⊦ mkDecimal(dec.int, dec.scale).int = dec.int
Used terms: dec.int