Nuprl Lemma : fpf-join-ap-sq

∀[A:Type]. ∀[eq:EqDecider(A)]. ∀[f:a:A fp-> Top]. ∀[g:Top]. ∀[x:A].  (f ⊕ g(x) ~ if x ∈ dom(f) then f(x) else g(x) fi )


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),  ifthenelse: if b then t else f fi ,  uall: ∀[x:A]. B[x],  top: Top,  universe: Type,  sqequal: s ~ t
Definitions unfolded in proof :  fpf-ap: f(x),  fpf-join: f ⊕ g,  pi2: snd(t),  fpf-cap: f(x)?z,  member: t ∈ T,  uall: ∀[x:A]. B[x],  so_lambda: λ2x.t[x],  so_apply: x[s],  all: ∀x:A. B[x],  implies: P ⇒ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  ifthenelse: if b then t else f fi ,  bfalse: ff,  prop: ℙ
Lemmas referenced :  fpf-dom_wf,  bool_wf,  equal-wf-T-base,  assert_wf,  bnot_wf,  not_wf,  top_wf,  fpf_wf,  deq_wf,  eqtt_to_assert,  uiff_transitivity,  eqff_to_assert,  assert_of_bnot,  equal_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  sqequalRule,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  cumulativity,  hypothesisEquality,  hypothesis,  because_Cache,  equalityTransitivity,  equalitySymmetry,  baseClosed,  lambdaEquality,  universeEquality,  isect_memberFormation,  sqequalAxiom,  isect_memberEquality,  lambdaFormation,  unionElimination,  equalityElimination,  productElimination,  independent_isectElimination,  independent_functionElimination,  dependent_functionElimination

Latex:
\mforall{}[A:Type].  \mforall{}[eq:EqDecider(A)].  \mforall{}[f:a:A  fp->  Top].  \mforall{}[g:Top].  \mforall{}[x:A].
    (f  \moplus{}  g(x)  \msim{}  if  x  \mmember{}  dom(f)  then  f(x)  else  g(x)  fi  )



Date html generated: 2018_05_21-PM-09_21_50
Last ObjectModification: 2018_02_09-AM-10_18_30

Theory : finite!partial!functions


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