Nuprl Lemma : apply-ifthenelse2

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


Proof




Definitions occuring in Statement :  ifthenelse: if then else fi  bool: 𝔹 uall: [x:A]. B[x] so_apply: x[s] function: x:A ⟶ B[x] universe: Type sqequal: t
Definitions unfolded in proof :  bool: 𝔹 ifthenelse: if then else 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


Home Index