BT010F

floor_sqrt_le_third_quotient

Alpha v34 checked-use theorem · independently kernel and Lean verified; not Stable

The floor root is at most the quotient of the doubled input by three.

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 n s q r. (exists bcf_lt_gap_b5rbfsltq_positive. bcf_lt_gap_b5rbfsltq_positive + S (2) = n) -> (((exists bcs_sqrt_lower_gap_b5rbfsltq_floor. bcs_sqrt_lower_gap_b5rbfsltq_floor + (s) * (s) = (n + n)) /\ exists bcs_sqrt_upper_gap_b5rbfsltq_floor. bcs_sqrt_upper_gap_b5rbfsltq_floor + S (n + n) = S (s) * S (s))) -> (((n + n) = (3) * (q) + (r) /\ (exists bcf_lt_gap_b5rbfsltq_division_bound. bcf_lt_gap_b5rbfsltq_division_bound + S (r) = 3))) -> (exists bcf_le_gap_b5rbfsltq_result. bcf_le_gap_b5rbfsltq_result + (s) = q)

Structural proof guide

The floor root is at most the quotient of the doubled input by three.

Direct prerequisites: floor_sqrt_three_mul_le_double, division_quotient_lower_of_scaled_le. The authored body proceeds by intermediate claims (1).

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

21 script commands · 3 reading checkpoints · 1 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 (2)
01Fix variables and assumptionsL1–7

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

  1. L1
    intro n
  2. L2
    intro s
  3. L3
    intro q
  4. L4
    intro r
  5. L5
    intro hpositive
  6. L6
    intro hfloor
  7. L7
    intro hdivision
02Establish hscaledL8–17

Establish this local claim before using it. It is not an additional assumption. The following proof commands apply floor sqrt three mul le double.

  1. L8
    have hscaled : exists bcf_le_gap_b5rbfsltq_scaled. bcf_le_gap_b5rbfsltq_scaled + (3 * s) = n + n
  2. L9
    specialize floor_sqrt_three_mul_le_double n
  3. L10
    specialize floor_sqrt_three_mul_le_double s
  4. L11
    apply floor_sqrt_three_mul_le_double
  5. L12
    exact hpositive
  6. L13
    exact hfloor
  7. L14
    specialize division_quotient_lower_of_scaled_le 3
  8. L15
    specialize division_quotient_lower_of_scaled_le (n + n)
  9. L16
    specialize division_quotient_lower_of_scaled_le q
  10. L17
    specialize division_quotient_lower_of_scaled_le r
03Use earlier factsL18–21

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

  1. L18
    specialize division_quotient_lower_of_scaled_le s
  2. L19
    apply division_quotient_lower_of_scaled_le
  3. L20
    exact hdivision
  4. L21
    exact hscaled

Library-wide reading audit

Original exact command ledger · 21 lines
  1. 0001intro n
  2. 0002intro s
  3. 0003intro q
  4. 0004intro r
  5. 0005intro hpositive
  6. 0006intro hfloor
  7. 0007intro hdivision
  8. 0008have hscaled : exists bcf_le_gap_b5rbfsltq_scaled. bcf_le_gap_b5rbfsltq_scaled + (3 * s) = n + n
  9. 0009specialize floor_sqrt_three_mul_le_double n
  10. 0010specialize floor_sqrt_three_mul_le_double s
  11. 0011apply floor_sqrt_three_mul_le_double
  12. 0012exact hpositive
  13. 0013exact hfloor
  14. 0014specialize division_quotient_lower_of_scaled_le 3
  15. 0015specialize division_quotient_lower_of_scaled_le (n + n)
  16. 0016specialize division_quotient_lower_of_scaled_le q
  17. 0017specialize division_quotient_lower_of_scaled_le r
  18. 0018specialize division_quotient_lower_of_scaled_le s
  19. 0019apply division_quotient_lower_of_scaled_le
  20. 0020exact hdivision
  21. 0021exact hscaled