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 then else fi  uimplies: supposing a uall: [x:A]. B[x] so_apply: x[s] function: x:A ⟶ B[x] universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a ifthenelse: if then else 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: subtype_rel: A ⊆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


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