Exact expanded PA statement
forall a b c. a + (b + c) = b + (a + c)Structural proof guide
Swap the first two addends under a fixed trailing addend.
Direct prerequisites: add_assoc, add_comm. The authored body proceeds by direct introduction and elimination.
Proof neighborhood
Direct dependencies
Direct dependents
Formal native tactic body
Dependencies are hypotheses of this body receipt. The focused endpoint audits separately check the complete empty-context certificates.