Nuprl Lemma : fseg_nil

[T:Type]. ∀L:T List. (fseg(T;L;[]) ⇐⇒ ↑null(L))


Proof




Definitions occuring in Statement :  fseg: fseg(T;L1;L2) null: null(as) nil: [] list: List assert: b uall: [x:A]. B[x] all: x:A. B[x] iff: ⇐⇒ Q universe: Type
Definitions unfolded in proof :  fseg: fseg(T;L1;L2) uall: [x:A]. B[x] all: x:A. B[x] member: t ∈ T so_lambda: λ2x.t[x] so_apply: x[s] implies:  Q assert: b ifthenelse: if then else fi  btrue: tt top: Top bfalse: ff prop: iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q decidable: Dec(P) or: P ∨ Q true: True not: ¬A false: False exists: x:A. B[x] append: as bs so_lambda: so_lambda(x,y,z.t[x; y; z]) so_apply: x[s1;s2;s3] uiff: uiff(P;Q) uimplies: supposing a
Lemmas referenced :  list_induction iff_wf exists_wf list_wf equal-wf-base-T assert_wf null_wf null_nil_lemma null_cons_lemma append_wf decidable__true nil_wf list_ind_nil_lemma cons_wf false_wf decidable__false btrue_wf append_is_nil and_wf equal_wf bfalse_wf btrue_neq_bfalse
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep isect_memberFormation lambdaFormation cut thin introduction extract_by_obid sqequalHypSubstitution isectElimination hypothesisEquality lambdaEquality hypothesis because_Cache independent_functionElimination rename dependent_functionElimination isect_memberEquality voidElimination voidEquality baseClosed independent_pairFormation unionElimination natural_numberEquality dependent_pairFormation productElimination equalitySymmetry independent_isectElimination dependent_set_memberEquality equalityTransitivity applyLambdaEquality setElimination addLevel levelHypothesis

Latex:
\mforall{}[T:Type].  \mforall{}L:T  List.  (fseg(T;L;[])  \mLeftarrow{}{}\mRightarrow{}  \muparrow{}null(L))



Date html generated: 2018_05_21-PM-06_30_24
Last ObjectModification: 2018_05_19-PM-04_40_56

Theory : general


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