Nuprl Lemma : quotient-equality
∀[T:Type]. ∀[E1,E2:T ⟶ T ⟶ ℙ].
  ((x,y:T//E1[x;y]) = (x,y:T//E2[x;y]) ∈ Type) supposing (EquivRel(T;x,y.E1[x;y]) and (∀x,y:T.  (E2[x;y] 
⇐⇒ E1[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]
, 
iff: P 
⇐⇒ Q
, 
function: x:A ⟶ B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
quotient: x,y:A//B[x; y]
, 
and: P ∧ Q
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s1;s2]
, 
subtype_rel: A ⊆r B
, 
cand: A c∧ B
, 
equiv_rel: EquivRel(T;x,y.E[x; y])
, 
trans: Trans(T;x,y.E[x; y])
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
guard: {T}
, 
so_lambda: λ2x y.t[x; y]
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
uimplies: b supposing a
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
sym: Sym(T;x,y.E[x; y])
Lemmas referenced : 
equal-wf-base, 
equiv_rel_wf, 
all_wf, 
iff_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
pertypeEquality, 
productEquality, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
because_Cache, 
hypothesis, 
applyEquality, 
functionExtensionality, 
cumulativity, 
lambdaEquality, 
universeEquality, 
productElimination, 
equalityTransitivity, 
equalitySymmetry, 
independent_pairFormation, 
dependent_functionElimination, 
independent_functionElimination, 
functionEquality, 
isect_memberFormation, 
isect_memberEquality, 
axiomEquality
Latex:
\mforall{}[T:Type].  \mforall{}[E1,E2:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].
    ((x,y:T//E1[x;y])  =  (x,y:T//E2[x;y]))  supposing 
          (EquivRel(T;x,y.E1[x;y])  and 
          (\mforall{}x,y:T.    (E2[x;y]  \mLeftarrow{}{}\mRightarrow{}  E1[x;y])))
Date html generated:
2016_10_21-AM-09_43_41
Last ObjectModification:
2016_08_09-PM-00_18_17
Theory : quot_1
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