Nuprl Lemma : fset-null_wf

[T:Type]. ∀[s:fset(T)].  (fset-null(s) ∈ 𝔹)


Proof




Definitions occuring in Statement :  fset-null: fset-null(s) fset: fset(T) bool: 𝔹 uall: [x:A]. B[x] member: t ∈ T universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T fset: fset(T) quotient: x,y:A//B[x; y] and: P ∧ Q fset-null: fset-null(s) prop: all: x:A. B[x] implies:  Q or: P ∨ Q cons: [a b] top: Top set-equal: set-equal(T;x;y) iff: ⇐⇒ Q rev_implies:  Q uimplies: supposing a not: ¬A false: False
Lemmas referenced :  bool_wf equal-wf-base list_wf set-equal_wf fset_wf equal_wf list-cases null_nil_lemma btrue_wf product_subtype_list null_cons_lemma cons_member l_member_wf member-implies-null-eq-bfalse nil_wf btrue_neq_bfalse bfalse_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut sqequalHypSubstitution pointwiseFunctionalityForEquality extract_by_obid hypothesis sqequalRule pertypeElimination productElimination thin productEquality isectElimination cumulativity hypothesisEquality because_Cache axiomEquality equalityTransitivity equalitySymmetry isect_memberEquality universeEquality lambdaFormation dependent_functionElimination independent_functionElimination unionElimination promote_hyp hypothesis_subsumption rename voidElimination voidEquality inlFormation independent_isectElimination

Latex:
\mforall{}[T:Type].  \mforall{}[s:fset(T)].    (fset-null(s)  \mmember{}  \mBbbB{})



Date html generated: 2017_04_17-AM-09_19_53
Last ObjectModification: 2017_02_27-PM-05_23_26

Theory : finite!sets


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