BT001D

lt_of_lt_of_le

Stable checked-use theorem · independently kernel verified

Strict order followed by weak order remains strict.

Current library: Alpha v34, 4,223 checked-use theorems; Stable remains 432. Historical first admissions, original proof editions, and non-admitted aliases are preserved. Exact original first-admission records.

Exact expanded PA statement

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

Structural proof guide

Strict order followed by weak order remains strict.

Direct prerequisites: le_trans. The authored body proceeds by direct introduction and elimination.

Proof neighborhood

Direct dependencies

Direct dependents

Formal native tactic body

Dependencies are hypotheses of the historical Alpha-v12 body receipt. The complete historical Alpha-v18 proof bundle independently checks every dependency; current Alpha v25 preserves that checked theorem use without changing Stable membership.

Read the argument

Proof checkpoints

11 script commands · 2 reading checkpoints · 0 local claims

This is a reading aid, not a new proof or a proof-tree certificate. Checkpoint groups are consecutive commands, not inferred branch boundaries. Every step links to the preserved script.

Named ingredients (1)
01Fix variables and assumptionsL1–5

Work with arbitrary variables or the premises of the current implication.

  1. L1
    intro a
  2. L2
    intro b
  3. L3
    intro c
  4. L4
    intro hab
  5. L5
    intro hbc
02Use earlier factsL6–11

Instantiate or apply named facts and discharge the corresponding proof obligations.

  1. L6
    specialize le_trans (S a)
  2. L7
    specialize le_trans b
  3. L8
    specialize le_trans c
  4. L9
    apply le_trans
  5. L10
    exact hab
  6. L11
    exact hbc

Library-wide reading audit

Original exact command ledger · 11 lines
  1. 0001intro a
  2. 0002intro b
  3. 0003intro c
  4. 0004intro hab
  5. 0005intro hbc
  6. 0006specialize le_trans (S a)
  7. 0007specialize le_trans b
  8. 0008specialize le_trans c
  9. 0009apply le_trans
  10. 0010exact hab
  11. 0011exact hbc