Nuprl Lemma : rleq*_functionality

∀a,b,c,d:ℝ*.  (a = b ⇒ c = d ⇒ (a ≤ c ⇐⇒ b ≤ d))


Proof




Definitions occuring in Statement :  rleq*: x ≤ y,  req*: x = y,  real*: ℝ*,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  implies: P ⇒ Q
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  iff: P ⇐⇒ Q,  and: P ∧ Q,  rleq*: x ≤ y,  member: t ∈ T,  prop: ℙ,  uall: ∀[x:A]. B[x],  rev_implies: P ⇐ Q,  guard: {T},  uimplies: b supposing a
Lemmas referenced :  rleq*_wf,  req*_wf,  real*_wf,  rrel*_functionality,  rleq_wf,  real_wf,  req_inversion,  rleq_transitivity,  rleq_weakening,  req_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  independent_pairFormation,  sqequalHypSubstitution,  cut,  introduction,  extract_by_obid,  isectElimination,  thin,  hypothesisEquality,  hypothesis,  lambdaEquality,  independent_functionElimination,  sqequalRule,  independent_isectElimination,  because_Cache,  dependent_functionElimination,  productElimination

Latex:
\mforall{}a,b,c,d:\mBbbR{}*.    (a  =  b  {}\mRightarrow{}  c  =  d  {}\mRightarrow{}  (a  \mleq{}  c  \mLeftarrow{}{}\mRightarrow{}  b  \mleq{}  d))



Date html generated: 2018_05_22-PM-03_20_23
Last ObjectModification: 2017_10_06-PM-06_06_32

Theory : reals_2


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