Nuprl Lemma : member-reverse

[T:Type]. ∀L:T List. ∀x:T.  ((x ∈ rev(L)) ⇐⇒ (x ∈ L))


Proof




Definitions occuring in Statement :  l_member: (x ∈ l) reverse: rev(as) list: List uall: [x:A]. B[x] all: x:A. B[x] iff: ⇐⇒ Q universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q implies:  Q l_member: (x ∈ l) exists: x:A. B[x] cand: c∧ B member: t ∈ T prop: rev_implies:  Q squash: T nat: int_seg: {i..j-} lelt: i ≤ j < k le: A ≤ B true: True subtype_rel: A ⊆B uimplies: supposing a guard: {T} top: Top so_lambda: λ2x.t[x] so_apply: x[s] sq_stable: SqStable(P) subtract: m uiff: uiff(P;Q) nat_plus: + less_than: a < b less_than': less_than'(a;b) not: ¬A false: False ge: i ≥  decidable: Dec(P) or: P ∨ Q sq_type: SQType(T)
Lemmas referenced :  l_member_wf reverse_wf list_wf equal_wf squash_wf true_wf select-reverse lelt_wf length_wf iff_weakening_equal length-reverse subtract_wf non_neg_length length_wf_nat nat_wf set_subtype_base le_wf int_subtype_base less_than_wf select_wf sq_stable__le add-associates minus-one-mul add-swap add-commutes less-iff-le add_functionality_wrt_le le_reflexive minus-one-mul-top one-mul add-mul-special two-mul mul-distributes-right zero-mul add-zero not-le-2 minus-zero zero-add omega-shadow mul-distributes mul-associates le-add-cancel not-lt-2 minus-add minus-minus nat_properties decidable__le decidable__lt subtype_base_sq
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation independent_pairFormation sqequalHypSubstitution productElimination thin cut introduction extract_by_obid isectElimination cumulativity hypothesisEquality hypothesis universeEquality applyEquality lambdaEquality imageElimination equalityTransitivity equalitySymmetry because_Cache setElimination rename dependent_set_memberEquality natural_numberEquality sqequalRule imageMemberEquality baseClosed independent_isectElimination independent_functionElimination isect_memberEquality voidElimination voidEquality dependent_pairFormation sqequalIntensionalEquality intEquality dependent_functionElimination promote_hyp productEquality addLevel addEquality multiplyEquality levelHypothesis minusEquality unionElimination instantiate

Latex:
\mforall{}[T:Type].  \mforall{}L:T  List.  \mforall{}x:T.    ((x  \mmember{}  rev(L))  \mLeftarrow{}{}\mRightarrow{}  (x  \mmember{}  L))



Date html generated: 2017_04_14-AM-08_40_40
Last ObjectModification: 2017_02_27-PM-03_31_13

Theory : list_0


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