`plus(1, 2, C). C = 3.`
`plus(0, 3, C). C = 3.`
Isn't that a counterexample, showing how it is not injective?
`plus(1, 2, C). C = 3.`
`plus(0, 3, C). C = 3.`
Isn't that a counterexample, showing how it is not injective?