| ∀ a. rmdup(x0) -1l a = rmdup(x0 -l a) ⊦ a = a0, (a0 ∈ x0 ⊃ rmdup(x0);a0 ' + rmdup(x0)) -1l a = rmdup(a0 ' + (x0 -l a)) |
a0 ∈ x0, ∀ a. rmdup(x0) -1l a = rmdup(x0 -l a) ⊦ a = a0, (a0 ∈ x0 ⊃ rmdup(x0);a0 ' + rmdup(x0)) -1l a = rmdup(a0 ' + (x0 -l a))
∀ a. rmdup(x0) -1l a = rmdup(x0 -l a) ⊦ a0 ∈ x0, a = a0, (a0 ∈ x0 ⊃ rmdup(x0);a0 ' + rmdup(x0)) -1l a = rmdup(a0 ' + (x0 -l a))
Used formulas: a0 ∈ x0