Proofgold Proof

pf

Let x0 of type ο be given.

Let x1 of type ο be given.

Let x2 of type ο be given.

Assume H0: or (or x0 x1) x2.

Let x3 of type ο be given.

Assume H1: x0 ⟶ x3.

Assume H2: x1 ⟶ x3.

Assume H3: x2 ⟶ x3.

Apply H0 with x3 leaving 2 subgoals.

Assume H4: or x0 x1.

Apply H4 with x3 leaving 2 subgoals.

The subproof is completed by applying H1.

The subproof is completed by applying H2.

The subproof is completed by applying H3.

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