Nuprl Lemma : finite-quotient

A:Type. ∀R:A ⟶ A ⟶ ℙ.  (finite(A)  EquivRel(A;x,y.x y)  (∀x,y:A.  Dec(x y))  finite(x,y:A//(x 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: infix_ap: y all: x:A. B[x] implies:  Q function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  all: x:A. B[x] implies:  Q uall: [x:A]. B[x] member: t ∈ T iff: ⇐⇒ Q and: P ∧ Q exists: x:A. B[x] so_lambda: λ2y.t[x; y] infix_ap: y so_apply: x[s1;s2] uimplies: supposing a rev_implies:  Q prop: so_lambda: λ2x.t[x] so_apply: x[s] subtype_rel: A ⊆B quotient: x,y:A//B[x; y] squash: T guard: {T} l_member: (x ∈ l) cand: c∧ B nat: ge: i ≥  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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