Nuprl Lemma : quotient-member-eq
∀[T:Type]. ∀[E:T ⟶ T ⟶ ℙ].  ∀x,y:T.  (E[x;y] 
⇒ (x = y ∈ (x,y:T//E[x;y]))) supposing EquivRel(T;x,y.E[x;y])
Proof
Definitions occuring in Statement : 
equiv_rel: EquivRel(T;x,y.E[x; y])
, 
quotient: x,y:A//B[x; y]
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s1;s2]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
so_apply: x[s1;s2]
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
so_lambda: λ2x y.t[x; y]
, 
quotient: x,y:A//B[x; y]
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
squash: ↓T
, 
guard: {T}
, 
true: True
, 
equiv_rel: EquivRel(T;x,y.E[x; y])
, 
refl: Refl(T;x,y.E[x; y])
Lemmas referenced : 
subtype_rel_self, 
equiv_rel_wf, 
istype-universe, 
quotient_wf, 
equal_wf, 
squash_wf, 
true_wf, 
subtype_quotient, 
equal_functionality_wrt_subtype_rel2, 
equal-wf-base-T, 
subtype_rel_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
introduction, 
cut, 
Error :lambdaFormation_alt, 
hypothesis, 
Error :universeIsType, 
applyEquality, 
hypothesisEquality, 
thin, 
sqequalRule, 
instantiate, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
universeEquality, 
Error :inhabitedIsType, 
Error :lambdaEquality_alt, 
dependent_functionElimination, 
axiomEquality, 
Error :functionIsTypeImplies, 
Error :isect_memberEquality_alt, 
Error :isectIsTypeImplies, 
Error :functionIsType, 
because_Cache, 
pointwiseFunctionality, 
pertypeMemberEquality, 
equalityTransitivity, 
equalitySymmetry, 
independent_isectElimination, 
independent_pairFormation, 
imageElimination, 
independent_functionElimination, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
Error :dependent_set_memberEquality_alt, 
Error :productIsType, 
Error :equalityIsType3, 
applyLambdaEquality, 
setElimination, 
rename, 
productElimination, 
Error :equalityIsType1, 
hyp_replacement
Latex:
\mforall{}[T:Type].  \mforall{}[E:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].    \mforall{}x,y:T.    (E[x;y]  {}\mRightarrow{}  (x  =  y))  supposing  EquivRel(T;x,y.E[x;y])
Date html generated:
2019_06_20-PM-00_32_07
Last ObjectModification:
2018_11_24-AM-09_34_59
Theory : quot_1
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