Nuprl Lemma : before-adjacent

[T:Type]
  ∀L:T List. ∀x,y:T.
    adjacent(T;L;x;y)  (∀z:T. (z before y ∈  (z before x ∈ L ∨ (z x ∈ T)))) supposing no_repeats(T;L)


Proof




Definitions occuring in Statement :  adjacent: adjacent(T;L;x;y) l_before: before y ∈ l no_repeats: no_repeats(T;l) list: List uimplies: supposing a uall: [x:A]. B[x] all: x:A. B[x] implies:  Q or: P ∨ Q universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] member: t ∈ T so_lambda: λ2x.t[x] uimplies: supposing a prop: implies:  Q or: P ∨ Q so_apply: x[s] false: False iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q guard: {T} uiff: uiff(P;Q) squash: T true: True subtype_rel: A ⊆B not: ¬A cand: c∧ B
Lemmas referenced :  list_induction all_wf isect_wf no_repeats_wf adjacent_wf l_before_wf or_wf equal_wf list_wf no_repeats_witness nil_wf cons_wf adjacent-nil adjacent-cons cons_before l_member_wf no_repeats_cons hd-before l_before_member2 no_repeats_iff not_wf squash_wf true_wf iff_weakening_equal l_before_antisymmetry adjacent-member
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation cut thin introduction extract_by_obid sqequalHypSubstitution isectElimination hypothesisEquality sqequalRule lambdaEquality cumulativity because_Cache hypothesis functionEquality independent_functionElimination rename dependent_functionElimination universeEquality independent_isectElimination voidElimination productElimination unionElimination addLevel orFunctionality productEquality inrFormation equalityTransitivity equalitySymmetry applyEquality imageElimination natural_numberEquality imageMemberEquality baseClosed hyp_replacement applyLambdaEquality inlFormation independent_pairFormation

Latex:
\mforall{}[T:Type]
    \mforall{}L:T  List.  \mforall{}x,y:T.
        adjacent(T;L;x;y)  {}\mRightarrow{}  (\mforall{}z:T.  (z  before  y  \mmember{}  L  {}\mRightarrow{}  (z  before  x  \mmember{}  L  \mvee{}  (z  =  x)))) 
        supposing  no\_repeats(T;L)



Date html generated: 2018_05_21-PM-06_39_31
Last ObjectModification: 2017_07_26-PM-04_53_27

Theory : general


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