Nuprl Lemma : sorted-by-append1

∀[T:Type]. ∀[R:T ⟶ T ⟶ ℙ].  ∀x:T. ∀L:T List.  (sorted-by(R;L @ [x]) ⇐⇒ sorted-by(R;L) ∧ (∀z∈L.R z x))


Proof




Definitions occuring in Statement :  sorted-by: sorted-by(R;L),  l_all: (∀x∈L.P[x]),  append: as @ bs,  cons: [a / b],  nil: [],  list: T List,  uall: ∀[x:A]. B[x],  prop: ℙ,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  apply: f a,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  member: t ∈ T,  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  rev_implies: P ⇐ Q,  subtype_rel: A ⊆r B,  so_lambda: λ2x.t[x],  prop: ℙ,  so_apply: x[s],  uimplies: b supposing a,  istype: istype(T),  top: Top,  append: as @ bs,  so_lambda: so_lambda(x,y,z.t[x; y; z]),  so_apply: x[s1;s2;s3],  guard: {T}
Lemmas referenced :  sorted-by-reverse,  sorted-by-cons,  reverse-append,  cons_wf,  nil_wf,  append_wf,  sorted-by_wf,  subtype_rel_dep_function,  l_member_wf,  l_all_wf,  list_wf,  istype-universe,  reverse-cons,  istype-void,  reverse_nil_lemma,  list_ind_nil_lemma,  list_ind_cons_lemma,  reverse_wf,  l_all_iff,  member-reverse
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :isect_memberFormation_alt,  Error :lambdaFormation_alt,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  because_Cache,  Error :lambdaEquality_alt,  applyEquality,  Error :inhabitedIsType,  sqequalRule,  hypothesis,  productElimination,  independent_functionElimination,  dependent_functionElimination,  independent_pairFormation,  promote_hyp,  Error :universeIsType,  instantiate,  cumulativity,  functionEquality,  universeEquality,  setEquality,  setElimination,  rename,  equalityTransitivity,  equalitySymmetry,  Error :setIsType,  independent_isectElimination,  Error :productIsType,  Error :functionIsType,  Error :isect_memberEquality_alt,  voidElimination

Latex:
\mforall{}[T:Type].  \mforall{}[R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].
    \mforall{}x:T.  \mforall{}L:T  List.    (sorted-by(R;L  @  [x])  \mLeftarrow{}{}\mRightarrow{}  sorted-by(R;L)  \mwedge{}  (\mforall{}z\mmember{}L.R  z  x))



Date html generated: 2019_06_20-PM-01_45_05
Last ObjectModification: 2018_10_06-PM-11_56_11

Theory : list_1


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