Nuprl Lemma : apply-ifthenelse2

∀[T1,U1,T2,U2:Type]. ∀[x:T1]. ∀[y:T2]. ∀[b:𝔹]. ∀[f:if b then T1 ⟶ U1 else T2 ⟶ U2 fi ].
  (f[if b then x else y fi ] ~ if b then f[x] else f[y] fi )


Proof




Definitions occuring in Statement :  ifthenelse: if b then t else f fi ,  bool: 𝔹,  uall: ∀[x:A]. B[x],  so_apply: x[s],  function: x:A ⟶ B[x],  universe: Type,  sqequal: s ~ t
Definitions unfolded in proof :  bool: 𝔹,  ifthenelse: if b then t else f fi ,  member: t ∈ T,  uall: ∀[x:A]. B[x]
Lemmas referenced :  ifthenelse_wf,  bool_wf
Rules used in proof :  sqequalHypSubstitution,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  unionElimination,  thin,  sqequalRule,  cut,  instantiate,  lemma_by_obid,  isectElimination,  hypothesisEquality,  universeEquality,  functionEquality,  hypothesis,  because_Cache,  isect_memberFormation,  introduction,  sqequalAxiom,  isect_memberEquality

Latex:
\mforall{}[T1,U1,T2,U2:Type].  \mforall{}[x:T1].  \mforall{}[y:T2].  \mforall{}[b:\mBbbB{}].  \mforall{}[f:if  b  then  T1  {}\mrightarrow{}  U1  else  T2  {}\mrightarrow{}  U2  fi  ].
    (f[if  b  then  x  else  y  fi  ]  \msim{}  if  b  then  f[x]  else  f[y]  fi  )



Date html generated: 2016_05_13-PM-04_01_26
Last ObjectModification: 2015_12_26-AM-10_49_08

Theory : bool_1


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