Nuprl Lemma : has-value-implies-dec-isaxiom-2

∀t:Base. ((t)↓ ⇒ ((t ~ Ax) ∨ (∀a,b:Base.  (if t = Ax then a otherwise b ~ b))))


Proof




Definitions occuring in Statement :  has-value: (a)↓,  isaxiom: if z = Ax then a otherwise b,  all: ∀x:A. B[x],  implies: P ⇒ Q,  or: P ∨ Q,  base: Base,  sqequal: s ~ t,  axiom: Ax
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  or: P ∨ Q,  prop: ℙ,  uall: ∀[x:A]. B[x],  so_lambda: λ2x.t[x],  so_apply: x[s],  guard: {T},  uimplies: b supposing a,  has-value: (a)↓,  false: False,  top: Top,  sq_type: SQType(T)
Lemmas referenced :  top_wf,  not_zero_sqequal_one,  is-exception_wf,  has-value_wf_base,  subtype_rel_self,  subtype_base_sq,  base_wf,  all_wf,  has-value-implies-dec-isaxiom
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  lemma_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  baseClosed,  independent_functionElimination,  hypothesis,  unionElimination,  inlFormation,  isectElimination,  sqequalRule,  lambdaEquality,  sqequalIntensionalEquality,  baseApply,  closedConclusion,  inrFormation,  instantiate,  because_Cache,  independent_isectElimination,  isaxiomCases,  divergentSqle,  voidElimination,  isect_memberFormation,  introduction,  sqequalAxiom,  isect_memberEquality,  voidEquality,  equalityTransitivity,  equalitySymmetry

Latex:
\mforall{}t:Base.  ((t)\mdownarrow{}  {}\mRightarrow{}  ((t  \msim{}  Ax)  \mvee{}  (\mforall{}a,b:Base.    (if  t  =  Ax  then  a  otherwise  b  \msim{}  b))))



Date html generated: 2016_05_13-PM-03_22_38
Last ObjectModification: 2016_01_14-PM-06_46_54

Theory : call!by!value_1


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