Exact expanded PA statement
forall a b c. (exists k. k + S a = b) -> (exists k. k + S b = c) -> exists k. k + S a = cStructural proof guide
Strict order is transitive.
Direct prerequisites: add_assoc, add_succ_left. The authored body proceeds by case analysis (2).
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.
- 0001
intro a - 0002
intro b - 0003
intro c - 0004
intro hab - 0005
intro hbc - 0006
cases hab - 0007
cases hbc - 0008
exists x1 + S x - 0009
trans x1 + (S x + S a) - 0010
apply add_assoc - 0011
trans x1 + S (x + S a) - 0012
congr - 0013
refl - 0014
apply add_succ_left - 0015
trans x1 + S b - 0016
congr - 0017
refl - 0018
congr - 0019
exact hab_witness - 0020
exact hbc_witness