Nuprl Lemma : fpf-union-join-dom

[A:Type]
  ∀eq:EqDecider(A). ∀f,g:a:A fp-> Top. ∀x:A. ∀R:Top.
    (↑x ∈ dom(fpf-union-join(eq;R;f;g)) ⇐⇒ (↑x ∈ dom(f)) ∨ (↑x ∈ dom(g)))


Proof




Definitions occuring in Statement :  fpf-union-join: fpf-union-join(eq;R;f;g) fpf-dom: x ∈ dom(f) fpf: a:A fp-> B[a] deq: EqDecider(T) assert: b uall: [x:A]. B[x] top: Top all: x:A. B[x] iff: ⇐⇒ Q or: P ∨ Q universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] member: t ∈ T so_lambda: λ2x.t[x] so_apply: x[s] fpf: a:A fp-> B[a] fpf-dom: x ∈ dom(f) fpf-union-join: fpf-union-join(eq;R;f;g) pi1: fst(t) iff: ⇐⇒ Q and: P ∧ Q implies:  Q or: P ∨ Q prop: rev_implies:  Q decidable: Dec(P) not: ¬A false: False
Lemmas referenced :  top_wf fpf_wf deq_wf l_member_wf or_wf and_wf assert_wf bnot_wf deq-member_wf member_filter filter_wf5 iff_wf member_append append_wf assert-deq-member decidable__assert not_wf iff_transitivity iff_weakening_uiff assert_of_bnot
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation cut lemma_by_obid hypothesis hypothesisEquality sqequalHypSubstitution isectElimination thin sqequalRule lambdaEquality universeEquality productElimination independent_pairFormation unionElimination inlFormation inrFormation addLevel independent_functionElimination orFunctionality dependent_functionElimination applyEquality cumulativity because_Cache setElimination rename setEquality impliesFunctionality orLevelFunctionality promote_hyp voidElimination andLevelFunctionality

Latex:
\mforall{}[A:Type]
    \mforall{}eq:EqDecider(A).  \mforall{}f,g:a:A  fp->  Top.  \mforall{}x:A.  \mforall{}R:Top.
        (\muparrow{}x  \mmember{}  dom(fpf-union-join(eq;R;f;g))  \mLeftarrow{}{}\mRightarrow{}  (\muparrow{}x  \mmember{}  dom(f))  \mvee{}  (\muparrow{}x  \mmember{}  dom(g)))



Date html generated: 2018_05_21-PM-09_23_23
Last ObjectModification: 2018_02_09-AM-10_19_17

Theory : finite!partial!functions


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