Nuprl Lemma : before-reverse

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


Proof




Definitions occuring in Statement :  l_before: before y ∈ l reverse: rev(as) list: List uall: [x:A]. B[x] all: x:A. B[x] iff: ⇐⇒ Q universe: Type
Definitions unfolded in proof :  prop: top: Top implies:  Q so_apply: x[s] so_lambda: λ2x.t[x] member: t ∈ T all: x:A. B[x] uall: [x:A]. B[x] rev_implies:  Q false: False and: P ∧ Q iff: ⇐⇒ Q or: P ∨ Q cand: c∧ B guard: {T}
Lemmas referenced :  reverse-cons reverse_nil_lemma list_wf reverse_wf l_before_wf iff_wf all_wf list_induction nil_wf nil_before append_wf cons_before l_before_append_iff equal_wf l_member_wf cons_wf or_wf singleton_before member_singleton member-reverse cons_member
Rules used in proof :  universeEquality dependent_functionElimination because_Cache voidEquality voidElimination isect_memberEquality rename independent_functionElimination hypothesis cumulativity lambdaEquality sqequalRule hypothesisEquality isectElimination sqequalHypSubstitution extract_by_obid introduction thin cut lambdaFormation isect_memberFormation sqequalReflexivity computationStep sqequalTransitivity sqequalSubstitution productElimination independent_pairFormation impliesFunctionality addLevel productEquality unionElimination Error :inrFormation_alt,  Error :productIsType,  Error :equalityIstype,  Error :inhabitedIsType,  Error :universeIsType,  Error :inlFormation_alt,  hyp_replacement equalitySymmetry applyLambdaEquality Error :unionIsType

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



Date html generated: 2019_06_20-PM-01_47_00
Last ObjectModification: 2019_01_15-PM-02_56_20

Theory : list_1


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