Nuprl Lemma : quo-lift_wf
∀A,B:Type. ∀f:A ⟶ B. ∀R:B ⟶ B ⟶ ℙ.  (EquivRel(B;x,y.x R y) 
⇒ (quo-lift(f) ∈ (x,y:A//(x R_f y)) ⟶ (x,y:B//(x R y))))
Proof
Definitions occuring in Statement : 
quo-lift: quo-lift(f)
, 
preima_of_rel: R_f
, 
equiv_rel: EquivRel(T;x,y.E[x; y])
, 
quotient: x,y:A//B[x; y]
, 
prop: ℙ
, 
infix_ap: x f y
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
uall: ∀[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
, 
quotient: x,y:A//B[x; y]
, 
and: P ∧ Q
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
preima_of_rel: R_f
, 
quo-lift: quo-lift(f)
Lemmas referenced : 
preima_of_equiv_rel, 
quotient_wf, 
equal-wf-base, 
preima_of_rel_wf, 
equiv_rel_wf, 
quotient-member-eq
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
independent_functionElimination, 
hypothesis, 
functionExtensionality, 
pointwiseFunctionalityForEquality, 
isectElimination, 
cumulativity, 
sqequalRule, 
lambdaEquality, 
applyEquality, 
independent_isectElimination, 
pertypeElimination, 
productElimination, 
productEquality, 
because_Cache, 
universeEquality, 
functionEquality
Latex:
\mforall{}A,B:Type.  \mforall{}f:A  {}\mrightarrow{}  B.  \mforall{}R:B  {}\mrightarrow{}  B  {}\mrightarrow{}  \mBbbP{}.
    (EquivRel(B;x,y.x  R  y)  {}\mRightarrow{}  (quo-lift(f)  \mmember{}  (x,y:A//(x  R\_f  y))  {}\mrightarrow{}  (x,y:B//(x  R  y))))
Date html generated:
2016_10_21-AM-09_44_13
Last ObjectModification:
2016_08_08-PM-09_15_45
Theory : quot_1
Home
Index