Nuprl Lemma : iseg-subtype

∀[A,B:Type].  ∀xs,ys:A List.  {xs ≤ ys ⇒ xs ≤ ys} supposing strong-subtype(A;B)


Proof




Definitions occuring in Statement :  iseg: l1 ≤ l2,  list: T List,  strong-subtype: strong-subtype(A;B),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  guard: {T},  all: ∀x:A. B[x],  implies: P ⇒ Q,  universe: Type
Definitions unfolded in proof :  guard: {T},  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  uimplies: b supposing a,  member: t ∈ T,  implies: P ⇒ Q,  prop: ℙ,  subtype_rel: A ⊆r B,  strong-subtype: strong-subtype(A;B),  cand: A c∧ B,  iseg: l1 ≤ l2,  exists: ∃x:A. B[x],  squash: ↓T,  label: ...$L... t,  true: True,  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  strong-subtype_witness,  iseg_wf,  subtype_rel_list,  strong-subtype_wf,  list_wf,  strong-subtype-equal-lists,  nth_tl_wf,  length_wf,  equal_wf,  nth_tl_append,  squash_wf,  true_wf,  append_wf,  iff_weakening_equal
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  isect_memberFormation,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  independent_functionElimination,  hypothesis,  rename,  cumulativity,  applyEquality,  because_Cache,  independent_isectElimination,  productElimination,  universeEquality,  equalityTransitivity,  equalitySymmetry,  hyp_replacement,  applyLambdaEquality,  dependent_pairFormation,  lambdaEquality,  imageElimination,  natural_numberEquality,  imageMemberEquality,  baseClosed

Latex:
\mforall{}[A,B:Type].    \mforall{}xs,ys:A  List.    \{xs  \mleq{}  ys  {}\mRightarrow{}  xs  \mleq{}  ys\}  supposing  strong-subtype(A;B)



Date html generated: 2017_04_17-AM-09_00_06
Last ObjectModification: 2017_02_27-PM-05_15_33

Theory : list_1


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