Nuprl Lemma : isaxiom-sqequal

∀[C:Base]
  ∀[A,B,z:Base].
    if z = Ax then A z otherwise B z ~ C z 
    supposing (A Ax ~ C Ax) ∧ ((∀a,b:Base.  (if z = Ax then a otherwise b ~ b)) ⇒ (B z ~ C z)) 
  supposing strict(C)


Proof




Definitions occuring in Statement :  strict: strict(F),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  isaxiom: if z = Ax then a otherwise b,  all: ∀x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  apply: f a,  base: Base,  sqequal: s ~ t,  axiom: Ax
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  has-value: (a)↓,  and: P ∧ Q,  cand: A c∧ B,  all: ∀x:A. B[x],  implies: P ⇒ Q,  or: P ∨ Q,  prop: ℙ,  so_lambda: λ2x.t[x],  so_apply: x[s],  guard: {T},  strict: strict(F)
Lemmas referenced :  strict_wf,  base_wf,  all_wf,  and_wf,  is-exception_wf,  has-value_wf_base,  has-value-implies-dec-isaxiom-2
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalSqle,  divergentSqle,  callbyvalueIsaxiom,  sqequalHypSubstitution,  hypothesis,  productElimination,  thin,  lemma_by_obid,  dependent_functionElimination,  hypothesisEquality,  independent_functionElimination,  unionElimination,  sqequalRule,  sqleReflexivity,  baseApply,  closedConclusion,  baseClosed,  lambdaFormation,  because_Cache,  isaxiomExceptionCases,  axiomSqleEquality,  isectElimination,  callbyvalueApply,  applyExceptionCases,  sqequalAxiom,  sqequalIntensionalEquality,  functionEquality,  lambdaEquality,  isect_memberEquality,  equalityTransitivity,  equalitySymmetry,  exceptionSqequal

Latex:
\mforall{}[C:Base]
    \mforall{}[A,B,z:Base].
        if  z  =  Ax  then  A  z  otherwise  B  z  \msim{}  C  z 
        supposing  (A  Ax  \msim{}  C  Ax)  \mwedge{}  ((\mforall{}a,b:Base.    (if  z  =  Ax  then  a  otherwise  b  \msim{}  b))  {}\mRightarrow{}  (B  z  \msim{}  C  z)) 
    supposing  strict(C)



Date html generated: 2016_05_13-PM-03_24_08
Last ObjectModification: 2016_01_14-PM-06_46_29

Theory : call!by!value_1


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