Proofgold Proof

pf

Let x0 of type (ι → ι) → ο be given.

Let x1 of type ι be given.

Let x2 of type ι be given.

Let x3 of type ι be given.

Assume H0: cdba9.. x0 x1 x2.

Assume H1: cdba9.. x0 x2 x3.

Let x4 of type ι → ι be given.

Assume H2: x0 x4.

Claim L3: x4 x1 = x4 x2

Apply H0 with x4.

The subproof is completed by applying H2.

Claim L4: x4 x2 = x4 x3

Apply H1 with x4.

The subproof is completed by applying H2.

Apply L3 with λ x5 x6 . x6 = x4 x3.

The subproof is completed by applying L4.

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