Nuprl Lemma : append_iseg

∀[T:Type]. ∀as,bs,cs:T List.  (as @ bs ≤ as @ cs ⇐⇒ bs ≤ cs)


Proof




Definitions occuring in Statement :  iseg: l1 ≤ l2,  append: as @ bs,  list: T List,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  universe: Type
Definitions unfolded in proof :  iseg: l1 ≤ l2,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  exists: ∃x:A. B[x],  member: t ∈ T,  prop: ℙ,  so_lambda: λ2x.t[x],  so_apply: x[s],  rev_implies: P ⇐ Q,  squash: ↓T,  true: True,  subtype_rel: A ⊆r B,  uimplies: b supposing a,  guard: {T},  top: Top
Lemmas referenced :  equal_wf,  list_wf,  append_wf,  exists_wf,  squash_wf,  true_wf,  iff_weakening_equal,  append_assoc,  length_wf,  append-cancellation
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  isect_memberFormation,  lambdaFormation,  independent_pairFormation,  sqequalHypSubstitution,  productElimination,  thin,  dependent_pairFormation,  hypothesisEquality,  cut,  introduction,  extract_by_obid,  isectElimination,  cumulativity,  hypothesis,  lambdaEquality,  applyEquality,  imageElimination,  equalityTransitivity,  equalitySymmetry,  universeEquality,  equalityUniverse,  levelHypothesis,  because_Cache,  natural_numberEquality,  imageMemberEquality,  baseClosed,  independent_isectElimination,  independent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality

Latex:
\mforall{}[T:Type].  \mforall{}as,bs,cs:T  List.    (as  @  bs  \mleq{}  as  @  cs  \mLeftarrow{}{}\mRightarrow{}  bs  \mleq{}  cs)



Date html generated: 2017_04_17-AM-08_45_32
Last ObjectModification: 2017_02_27-PM-05_04_16

Theory : list_1


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