Nuprl Lemma : fpf-join-cap-sq

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


Proof




Definitions occuring in Statement :  fpf-join: f ⊕ g fpf-cap: f(x)?z fpf-dom: x ∈ dom(f) fpf: a:A fp-> B[a] deq: EqDecider(T) ifthenelse: if then else fi  uall: [x:A]. B[x] top: Top universe: Type sqequal: t
Definitions unfolded in proof :  fpf-cap: f(x)?z uall: [x:A]. B[x] member: t ∈ T top: Top so_lambda: λ2x.t[x] so_apply: x[s] all: x:A. B[x] implies:  Q bool: 𝔹 unit: Unit it: btrue: tt assert: b ifthenelse: if then else fi  uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a bfalse: ff bnot: ¬bb false: False prop: iff: ⇐⇒ Q or: P ∨ Q not: ¬A rev_implies:  Q guard: {T}
Lemmas referenced :  fpf-join-ap-sq fpf-dom_wf fpf-join_wf top_wf bool_wf btrue_wf eqtt_to_assert eqff_to_assert equal_wf equal-wf-T-base assert_wf bnot_wf not_wf fpf-join-dom or_wf fpf_wf deq_wf uiff_transitivity assert_of_bnot
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity sqequalRule cut introduction extract_by_obid sqequalHypSubstitution isectElimination thin because_Cache hypothesisEquality isect_memberEquality voidElimination voidEquality hypothesis cumulativity lambdaEquality lambdaFormation unionElimination equalityElimination productElimination independent_isectElimination equalityTransitivity equalitySymmetry dependent_functionElimination independent_functionElimination baseClosed promote_hyp inlFormation inrFormation universeEquality isect_memberFormation sqequalAxiom

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



Date html generated: 2018_05_21-PM-09_21_54
Last ObjectModification: 2018_02_09-AM-10_18_31

Theory : finite!partial!functions


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