Nuprl Lemma : sublist-same-last

[T:Type]. ∀[L,L':T List].
  (last(L') last(L) ∈ T) supposing ((last(L) ∈ L') and L' ⊆ and (¬↑null(L')) and no_repeats(T;L) and (¬↑null(L)))


Proof




Definitions occuring in Statement :  sublist: L1 ⊆ L2 last: last(L) no_repeats: no_repeats(T;l) l_member: (x ∈ l) null: null(as) list: List assert: b 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 all: x:A. B[x] implies:  Q or: P ∨ Q prop: subtype_rel: A ⊆B top: Top iff: ⇐⇒ Q and: P ∧ Q false: False guard: {T}
Lemmas referenced :  l_tricotomy last_wf last_member l_member_wf sublist_wf not_wf assert_wf null_wf3 subtype_rel_list top_wf no_repeats_wf last-not-before no_repeats-sublist l_before_sublist
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut lemma_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality dependent_functionElimination independent_isectElimination hypothesis independent_functionElimination because_Cache unionElimination sqequalRule isect_memberEquality axiomEquality equalityTransitivity equalitySymmetry applyEquality lambdaEquality voidElimination voidEquality productElimination

Latex:
\mforall{}[T:Type].  \mforall{}[L,L':T  List].
    (last(L')  =  last(L))  supposing 
          ((last(L)  \mmember{}  L')  and 
          L'  \msubseteq{}  L  and 
          (\mneg{}\muparrow{}null(L'))  and 
          no\_repeats(T;L)  and 
          (\mneg{}\muparrow{}null(L)))



Date html generated: 2016_05_15-PM-03_42_17
Last ObjectModification: 2015_12_27-PM-01_18_39

Theory : general


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