IndisputableMonolith.Foundation.RealsFromLogic
This module constructs the recovered real line as the Cauchy completion of recovered rationals, with the Cauchy predicate evaluated after transport to standard rationals. Modules building complex numbers and transported transcendentals cite it to obtain an equivalence with Mathlib reals. The module supplies the relevant sequence type, quotient construction, and round-trip maps.
claimLet LogicRat be the recovered rationals. Define CauchySeqLogicRat as sequences in LogicRat whose image in $ℚ$ is Cauchy under the standard uniform structure. The recovered reals LogicReal are the resulting completion, equipped with maps toReal : LogicReal → $ℝ$ and fromReal : $ℝ$ → LogicReal that satisfy toReal ∘ fromReal = id and fromReal ∘ toReal = id.
background
The module continues the logic-derived number tower after RationalsFromLogic. It introduces recovered-rational Cauchy sequences by transporting the Cauchy predicate to Mathlib's $ℚ$ and its standard uniform structure; this is the precise step at which the rational layer enters the Cauchy completion. The resulting LogicReal carries explicit equivalence maps to the standard reals.
proof idea
This is a definition module. It defines the CauchySeqLogicRat predicate by transport to $ℚ$, constructs LogicReal as the quotient completion, and supplies the maps toReal, fromReal together with the round-trip lemmas toReal_fromReal and fromReal_toReal.
why it matters in Recognition Science
The module supplies LogicReal and its equivalence to $ℝ$ to ComplexFromLogic for the complex carrier, to LogicRealTranscendentals for transport of transcendental functions, and to RecoveredTowerAxiomAudit for the full tower audit. It fills the real-number step in the recovered tower LogicNat → LogicInt → LogicRat → LogicReal → LogicComplex.
scope and limits
- Does not develop analytic properties or integration on LogicReal.
- Does not construct the reals without using Mathlib's uniform structure on $ℚ$.
- Does not address other completions such as p-adics.
- Does not interpret the recovered reals in physical units or constants.
used by (3)
depends on (1)
declarations in this module (35)
-
structure
CauchySeqLogicRat -
structure
LogicReal -
def
toReal -
def
fromReal -
theorem
toReal_fromReal -
theorem
fromReal_toReal -
def
equivReal -
theorem
eq_iff_toReal_eq -
def
ofRatCore -
def
ofLogicRat -
theorem
toReal_ofRatCore -
theorem
toReal_ofLogicRat -
theorem
toReal_zero -
theorem
toReal_one -
theorem
toReal_add -
theorem
toReal_neg -
theorem
toReal_sub -
theorem
toReal_mul -
theorem
toReal_inv -
theorem
toReal_div -
theorem
le_iff_toReal_le -
theorem
lt_iff_toReal_lt -
theorem
add_assoc' -
theorem
add_comm' -
theorem
zero_add' -
theorem
add_zero' -
theorem
add_left_neg' -
theorem
mul_assoc' -
theorem
mul_comm' -
theorem
one_mul' -
theorem
mul_one' -
theorem
mul_add' -
theorem
add_mul' -
theorem
bourbaki_complete -
theorem
logicReal_recovered_from_completion