Nuprl Lemma : filter-filter2

∀[P1,P2,L:Top].  (filter(P2;filter(P1;L)) ~ filter(λt.((P1 t) ∧b (P2 t));L))


Proof




Definitions occuring in Statement :  filter: filter(P;l),  band: p ∧b q,  uall: ∀[x:A]. B[x],  top: Top,  apply: f a,  lambda: λx.A[x],  sqequal: s ~ t
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  top: Top
Lemmas referenced :  filter-filter,  top_wf
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  cut,  lemma_by_obid,  sqequalHypSubstitution,  sqequalTransitivity,  computationStep,  isectElimination,  thin,  isect_memberEquality,  voidElimination,  voidEquality,  hypothesis,  isect_memberFormation,  introduction,  sqequalAxiom,  hypothesisEquality,  because_Cache

Latex:
\mforall{}[P1,P2,L:Top].    (filter(P2;filter(P1;L))  \msim{}  filter(\mlambda{}t.((P1  t)  \mwedge{}\msubb{}  (P2  t));L))



Date html generated: 2016_05_14-PM-02_57_32
Last ObjectModification: 2015_12_26-PM-02_29_47

Theory : list_1


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