Nuprl Lemma : permutation-cons

∀[A:Type]
  ∀x:A. ∀L1,L2:A List.
    (permutation(A;[x / L1];L2) ⇐⇒ ∃as,bs:A List. ((L2 = (as @ [x / bs]) ∈ (A List)) ∧ permutation(A;L1;as @ bs)))


Proof




Definitions occuring in Statement :  permutation: permutation(T;L1;L2),  append: as @ bs,  cons: [a / b],  list: T List,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  member: t ∈ T,  prop: ℙ,  rev_implies: P ⇐ Q,  exists: ∃x:A. B[x],  so_lambda: λ2x.t[x],  top: Top,  so_apply: x[s],  l_contains: A ⊆ B,  l_all: (∀x∈L.P[x]),  int_seg: {i..j-},  lelt: i ≤ j < k,  le: A ≤ B,  less_than': less_than'(a;b),  false: False,  not: ¬A,  nat_plus: ℕ+,  less_than: a < b,  squash: ↓T,  true: True,  guard: {T},  decidable: Dec(P),  or: P ∨ Q,  uiff: uiff(P;Q),  uimplies: b supposing a,  satisfiable_int_formula: satisfiable_int_formula(fmla),  select: L[n],  cons: [a / b],  append: as @ bs,  so_lambda: so_lambda(x,y,z.t[x; y; z]),  so_apply: x[s1;s2;s3],  cand: A c∧ B
Lemmas referenced :  permutation_wf,  cons_wf,  exists_wf,  list_wf,  equal_wf,  append_wf,  length_wf,  length-append,  permutation_inversion,  permutation-contains,  length_of_cons_lemma,  false_wf,  add_nat_plus,  length_wf_nat,  less_than_wf,  nat_plus_wf,  nat_plus_properties,  decidable__lt,  add-is-int-iff,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformless_wf,  itermConstant_wf,  itermVar_wf,  itermAdd_wf,  intformeq_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_term_value_add_lemma,  int_formula_prop_eq_lemma,  int_formula_prop_wf,  lelt_wf,  l_member_decomp,  list_ind_cons_lemma,  list_ind_nil_lemma,  permutation_transitivity,  permutation-rotate,  nil_wf,  permutation_weakening,  append_functionality_wrt_permutation,  cons_cancel_wrt_permutation
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  independent_pairFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  cumulativity,  hypothesisEquality,  hypothesis,  productElimination,  sqequalRule,  lambdaEquality,  productEquality,  applyLambdaEquality,  isect_memberEquality,  voidElimination,  voidEquality,  universeEquality,  dependent_functionElimination,  independent_functionElimination,  because_Cache,  dependent_set_memberEquality,  natural_numberEquality,  imageMemberEquality,  baseClosed,  equalityTransitivity,  equalitySymmetry,  setElimination,  rename,  unionElimination,  pointwiseFunctionality,  promote_hyp,  baseApply,  closedConclusion,  independent_isectElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  computeAll,  addEquality,  hyp_replacement

Latex:
\mforall{}[A:Type]
    \mforall{}x:A.  \mforall{}L1,L2:A  List.
        (permutation(A;[x  /  L1];L2)
        \mLeftarrow{}{}\mRightarrow{}  \mexists{}as,bs:A  List.  ((L2  =  (as  @  [x  /  bs]))  \mwedge{}  permutation(A;L1;as  @  bs)))



Date html generated: 2017_04_17-AM-08_23_42
Last ObjectModification: 2017_02_27-PM-04_45_25

Theory : list_1


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