Nuprl Lemma : list-diff-cons-single

[T:Type]. ∀[eq:EqDecider(T)]. ∀[as:T List]. ∀[b,x:T].  [x as]-[b] [x as-[b]] ∈ (T List) supposing ¬(x b ∈ T)


Proof




Definitions occuring in Statement :  list-diff: as-bs cons: [a b] nil: [] list: List deq: EqDecider(T) uimplies: supposing a uall: [x:A]. B[x] not: ¬A universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a squash: T prop: true: True subtype_rel: A ⊆B guard: {T} iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q implies:  Q all: x:A. B[x] top: Top deq: EqDecider(T) bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) ifthenelse: if then else fi  bfalse: ff exists: x:A. B[x] or: P ∨ Q sq_type: SQType(T) bnot: ¬bb assert: b false: False not: ¬A
Lemmas referenced :  equal_wf squash_wf true_wf list-diff-cons cons_wf nil_wf list-diff_wf iff_weakening_equal deq_member_cons_lemma deq_member_nil_lemma bor_wf bfalse_wf bool_wf eqtt_to_assert assert-deq-member eqff_to_assert deq-member_wf bool_cases_sqequal subtype_base_sq bool_subtype_base assert-bnot l_member_wf not_wf list_wf deq_wf member_singleton
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut applyEquality thin lambdaEquality sqequalHypSubstitution imageElimination extract_by_obid isectElimination hypothesisEquality equalityTransitivity hypothesis equalitySymmetry because_Cache cumulativity natural_numberEquality sqequalRule imageMemberEquality baseClosed universeEquality independent_isectElimination productElimination independent_functionElimination dependent_functionElimination isect_memberEquality voidElimination voidEquality setElimination rename lambdaFormation unionElimination equalityElimination dependent_pairFormation promote_hyp instantiate axiomEquality

Latex:
\mforall{}[T:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[as:T  List].  \mforall{}[b,x:T].
    [x  /  as]-[b]  =  [x  /  as-[b]]  supposing  \mneg{}(x  =  b)



Date html generated: 2017_04_17-AM-09_12_58
Last ObjectModification: 2017_02_27-PM-05_19_52

Theory : decidable!equality


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