BT001F · Bertrand theorem

lt_trans

Stable checked-use theorem · independently kernel verified

Strict order is transitive.

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.

Statement with defined notation

∀ a. ∀ b. ∀ c. Lt(a,b) → Lt(b,c) → Lt(a,c)

Every purple notation token opens its conservative definition. Expanding the displayed statement recovers the exact first-order Peano-arithmetic formula checked by the unchanged kernel.

Definitions used by this theorem

In the theorem statement

PD0002 Lt

3 occurrences

In local proof propositions

none

0 occurrences

Exact expanded native-PA statement
forall a b c. (exists k. k + S a = b) -> (exists k. k + S b = c) -> exists k. k + S a = c

Proof neighborhood

Direct theorem prerequisites

BT0003 add_assoc BT0001 add_succ_left

Direct theorem dependents

BT00U0 four_power_central_recurrence_step BT00VH primorial_odd_interval_divides_middle BT0124 bertrand_small_closed_upper

Definition-aware tactic body

Only local propositions introduced by have or suffices are compacted. Every changed line has an exact-AST conservative-expansion receipt; the kernel still receives the immutable original tactic script.

Read the argument

Proof checkpoints

20 script commands · 9 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.

Definition notation is shown below. Open the paired exact edition for the original native formulas. Source pairing is not a new equivalence certificate.

Named ingredients (2)
add assocadd succ left
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
02Separate the logical casesL6–7

Follow the explicit conjunction, disjunction, witness, or contradiction step recorded below.

  1. L6
    cases hab
  2. L7
    cases hbc
03Construct an explicit witnessL8–8

Supply the displayed value, then prove that it has the required property.

  1. L8
    exists x1 + S x
04Calculate and transport equalitiesL9–9

Carry out the recorded arithmetic or equality steps; inspect the exact commands for their direction and premises.

  1. L9
    trans x1 + (S x + S a)
05Use earlier factsL10–10

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

  1. L10
    apply add_assoc
06Calculate and transport equalitiesL11–13

Carry out the recorded arithmetic or equality steps; inspect the exact commands for their direction and premises.

  1. L11
    trans x1 + S (x + S a)
  2. L12
    congr
  3. L13
    refl
07Use earlier factsL14–14

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

  1. L14
    apply add_succ_left
08Calculate and transport equalitiesL15–18

Carry out the recorded arithmetic or equality steps; inspect the exact commands for their direction and premises.

  1. L15
    trans x1 + S b
  2. L16
    congr
  3. L17
    refl
  4. L18
    congr
09Use earlier factsL19–20

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

  1. L19
    exact hab_witness
  2. L20
    exact hbc_witness

Library-wide reading audit

Original defined command ledger · 20 lines
  1. 0001intro a
  2. 0002intro b
  3. 0003intro c
  4. 0004intro hab
  5. 0005intro hbc
  6. 0006cases hab
  7. 0007cases hbc
  8. 0008exists x1 + S x
  9. 0009trans x1 + (S x + S a)
  10. 0010apply add_assoc
  11. 0011trans x1 + S (x + S a)
  12. 0012congr
  13. 0013refl
  14. 0014apply add_succ_left
  15. 0015trans x1 + S b
  16. 0016congr
  17. 0017refl
  18. 0018congr
  19. 0019exact hab_witness
  20. 0020exact hbc_witness