Nuprl Lemma : finite-quotient

∀A:Type. ∀R:A ⟶ A ⟶ ℙ.  (finite(A) ⇒ EquivRel(A;x,y.x R y) ⇒ (∀x,y:A.  Dec(x R y)) ⇒ finite(x,y:A//(x R y)))


Proof




Definitions occuring in Statement :  finite: finite(T),  equiv_rel: EquivRel(T;x,y.E[x; y]),  quotient: x,y:A//B[x; y],  decidable: Dec(P),  prop: ℙ,  infix_ap: x f y,  all: ∀x:A. B[x],  implies: P ⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  uall: ∀[x:A]. B[x],  member: t ∈ T,  iff: P ⇐⇒ Q,  and: P ∧ Q,  exists: ∃x:A. B[x],  so_lambda: λ2x y.t[x; y],  infix_ap: x f y,  so_apply: x[s1;s2],  uimplies: b supposing a,  rev_implies: P ⇐ Q,  prop: ℙ,  so_lambda: λ2x.t[x],  so_apply: x[s],  subtype_rel: A ⊆r B,  quotient: x,y:A//B[x; y],  squash: ↓T,  guard: {T},  l_member: (x ∈ l),  cand: A c∧ B,  nat: ℕ,  ge: i ≥ j ,  decidable: Dec(P),  or: P ∨ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  false: False,  not: ¬A,  top: Top,  sq_stable: SqStable(P)
Lemmas referenced :  finite-iff-listable,  quotient_wf,  all_wf,  decidable_wf,  equiv_rel_wf,  finite_wf,  decidable__quotient_equal,  remove-repeats_wf,  infix_ap_wf,  mk_deq_wf,  subtype_rel_list,  subtype_quotient,  no_repeats_wf,  l_member_wf,  remove-repeats-no_repeats,  squash_wf,  equal-wf-base,  equal_wf,  remove-repeats_property,  less_than_wf,  length_wf,  select_wf,  nat_properties,  decidable__le,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformle_wf,  itermConstant_wf,  itermVar_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  sq_stable__l_member
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  hypothesis,  productElimination,  independent_functionElimination,  cumulativity,  sqequalRule,  lambdaEquality,  applyEquality,  functionExtensionality,  independent_isectElimination,  functionEquality,  universeEquality,  rename,  dependent_pairFormation,  instantiate,  because_Cache,  productEquality,  independent_pairFormation,  dependent_functionElimination,  pointwiseFunctionalityForEquality,  pertypeElimination,  equalityTransitivity,  equalitySymmetry,  imageMemberEquality,  baseClosed,  promote_hyp,  hyp_replacement,  applyLambdaEquality,  setElimination,  natural_numberEquality,  unionElimination,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  computeAll,  imageElimination

Latex:
\mforall{}A:Type.  \mforall{}R:A  {}\mrightarrow{}  A  {}\mrightarrow{}  \mBbbP{}.
    (finite(A)  {}\mRightarrow{}  EquivRel(A;x,y.x  R  y)  {}\mRightarrow{}  (\mforall{}x,y:A.    Dec(x  R  y))  {}\mRightarrow{}  finite(x,y:A//(x  R  y)))



Date html generated: 2017_04_17-AM-09_34_11
Last ObjectModification: 2017_02_27-PM-05_33_55

Theory : equipollence!!cardinality!


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