Nuprl Lemma : fpf-join-ap

∀[A:Type]. ∀[B:A ⟶ Type]. ∀[eq:EqDecider(A)]. ∀[f,g:a:A fp-> B[a]]. ∀[x:A].
  f ⊕ g(x) = if x ∈ dom(f) then f(x) else g(x) fi  ∈ B[x] supposing ↑x ∈ dom(f ⊕ g)


Proof




Definitions occuring in Statement :  fpf-join: f ⊕ g,  fpf-ap: f(x),  fpf-dom: x ∈ dom(f),  fpf: a:A fp-> B[a],  deq: EqDecider(T),  assert: ↑b,  ifthenelse: if b then t else f fi ,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  so_apply: x[s],  function: x:A ⟶ B[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  ifthenelse: if b then t else f fi ,  fpf-dom: x ∈ dom(f),  deq-member: x ∈b L,  reduce: reduce(f;k;as),  list_ind: list_ind,  pi1: fst(t),  fpf-ap: f(x),  pi2: snd(t),  fpf-join: f ⊕ g,  fpf-cap: f(x)?z,  so_lambda: λ2x.t[x],  so_apply: x[s],  prop: ℙ,  subtype_rel: A ⊆r B,  all: ∀x:A. B[x],  top: Top
Lemmas referenced :  fpf-ap_wf,  fpf-join_wf,  assert_wf,  fpf-dom_wf,  top_wf,  subtype-fpf2,  deq_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalRule,  hypothesis,  lemma_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  lambdaEquality,  applyEquality,  independent_isectElimination,  because_Cache,  lambdaFormation,  isect_memberEquality,  voidElimination,  voidEquality,  axiomEquality,  equalityTransitivity,  equalitySymmetry

Latex:
\mforall{}[A:Type].  \mforall{}[B:A  {}\mrightarrow{}  Type].  \mforall{}[eq:EqDecider(A)].  \mforall{}[f,g:a:A  fp->  B[a]].  \mforall{}[x:A].
    f  \moplus{}  g(x)  =  if  x  \mmember{}  dom(f)  then  f(x)  else  g(x)  fi    supposing  \muparrow{}x  \mmember{}  dom(f  \moplus{}  g)



Date html generated: 2018_05_21-PM-09_21_45
Last ObjectModification: 2018_02_09-AM-10_18_26

Theory : finite!partial!functions


Home Index