BT001C

le_eq_or_lt

Stable ยท empty-context checked

A witnessed inequality is either equality or a witnessed strict inequality.

Exact expanded PA statement

forall a b. (exists k. k + a = b) -> a = b \/ exists k. k + S a = b

Structural proof guide

A witnessed inequality is either equality or a witnessed strict inequality.

Direct prerequisites: zero_or_succ, zero_add, add_succ_left. The authored body proceeds by case analysis (3), equality transport (3).

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.

  1. 0001intro a
  2. 0002intro b
  3. 0003intro h
  4. 0004cases h
  5. 0005specialize zero_or_succ x
  6. 0006cases zero_or_succ
  7. 0007left
  8. 0008rewrite zero_or_succ_left at h_witness
  9. 0009specialize zero_add a
  10. 0010rewrite zero_add at h_witness
  11. 0011exact h_witness
  12. 0012cases zero_or_succ_right
  13. 0013right
  14. 0014exists x1
  15. 0015trans S x1 + a
  16. 0016trans S (x1 + a)
  17. 0017apply PA4
  18. 0018symm
  19. 0019apply add_succ_left
  20. 0020rewrite <- zero_or_succ_right_witness
  21. 0021exact h_witness