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.
The initial 0/1 convergent is included: u is natural, not necessarily positive. Comparison denominators are strictly smaller and positive. Signed competitors are represented by an arbitrary difference rp−rn. Approximation inequalities are proved from the trace, never stored as assumptions in Convergent.
Exact theorem in conservative defined notation
∀ a. ∀ b. ∀ s. ContinuedFraction(a,b,s) → ∃ x. ∃ y. ∃ z. Convergent(s,x,y,z) ∧ a · z = b · y
Every linked abbreviation expands hygienically to the identical original native formula.
Definition DAG
Actual proof prerequisites
Complete tactic proof in conservative notation
All 26 original proof lines are preserved. Only local proposition formulas are abbreviated; every abbreviation has an exact binder-safe expansion check. The linked exact edition contains the unchanged replay script.
Read the argument
Proof checkpoints
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 assumptionsL1–4
02Separate the logical casesL5–11
Follow the explicit conjunction, disjunction, witness, or contradiction step recorded below.
03Establish htL12–20
Establish this local claim before using it. It is not an additional assumption. The following proof commands apply continued fraction exact terminal convergent exists.
- L12
have ht : ∃ u. ∃ v. Convergent(s,x4,u,v) ∧ a · v = b · uDefinitions: Convergent(s,x4,u,v)Original native command in the exact edition - L13
specialize continued_fraction_exact_terminal_convergent_exists (a) - L14
specialize continued_fraction_exact_terminal_convergent_exists (b) - L15
specialize continued_fraction_exact_terminal_convergent_exists (s) - L16
specialize continued_fraction_exact_terminal_convergent_exists (x2) - L17
specialize continued_fraction_exact_terminal_convergent_exists (x3) - L18
specialize continued_fraction_exact_terminal_convergent_exists (x4) - L19
apply continued_fraction_exact_terminal_convergent_exists - L20
exact hcf_witness_witness_witness_witness_witness_right_right
04Separate the logical casesL21–22
05Construct an explicit witnessL23–25
06Use earlier factsL26–26
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L26
exact ht_witness_witness
Original defined command ledger · 26 lines
- 0001
intro a - 0002
intro b - 0003
intro s - 0004
intro hcf - 0005
cases hcf - 0006
cases hcf_witness - 0007
cases hcf_witness_witness - 0008
cases hcf_witness_witness_witness - 0009
cases hcf_witness_witness_witness_witness - 0010
cases hcf_witness_witness_witness_witness_witness - 0011
cases hcf_witness_witness_witness_witness_witness_right - 0012
have ht : ∃ u. ∃ v. Convergent(s,x4,u,v) ∧ a · v = b · u - 0013
specialize continued_fraction_exact_terminal_convergent_exists (a) - 0014
specialize continued_fraction_exact_terminal_convergent_exists (b) - 0015
specialize continued_fraction_exact_terminal_convergent_exists (s) - 0016
specialize continued_fraction_exact_terminal_convergent_exists (x2) - 0017
specialize continued_fraction_exact_terminal_convergent_exists (x3) - 0018
specialize continued_fraction_exact_terminal_convergent_exists (x4) - 0019
apply continued_fraction_exact_terminal_convergent_exists - 0020
exact hcf_witness_witness_witness_witness_witness_right_right - 0021
cases ht - 0022
cases ht_witness - 0023
exists x4 - 0024
exists x5 - 0025
exists x6 - 0026
exact ht_witness_witness