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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