Nuprl Lemma : not-quotient-function-subtype
¬(∀[X,A:Type]. ∀[E:A ⟶ A ⟶ ℙ].
    (EquivRel(A;a,b.E[a;b]) 
⇒ ((X ⟶ (a,b:A//E[a;b])) ⊆r (f,g:X ⟶ A//fun-equiv(X;a,b.↓E[a;b];f;g)))))
Proof
Definitions occuring in Statement : 
fun-equiv: fun-equiv(X;a,b.E[a; b];f;g)
, 
equiv_rel: EquivRel(T;x,y.E[x; y])
, 
quotient: x,y:A//B[x; y]
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s1;s2]
, 
not: ¬A
, 
squash: ↓T
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
not: ¬A
, 
implies: P 
⇒ Q
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
prop: ℙ
, 
so_lambda: λ2x y.t[x; y]
, 
so_apply: x[s1;s2]
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
quotient: x,y:A//B[x; y]
, 
false: False
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
all: ∀x:A. B[x]
, 
true: True
, 
sq_type: SQType(T)
, 
guard: {T}
Lemmas referenced : 
istype-universe, 
equiv_rel_wf, 
subtype_rel_wf, 
quotient_wf, 
fun-equiv_wf, 
base_wf, 
true_wf, 
istype-base, 
equiv_rel_true, 
squash_wf, 
quotient-member-eq, 
subtype_base_sq, 
subtype_rel_self, 
int_subtype_base, 
fun-equiv-rel, 
equiv_rel_squash, 
quotient-squash
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :lambdaFormation_alt, 
sqequalRule, 
Error :isectIsType, 
cut, 
instantiate, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
universeEquality, 
hypothesis, 
Error :inhabitedIsType, 
hypothesisEquality, 
Error :functionIsType, 
Error :universeIsType, 
because_Cache, 
Error :lambdaEquality_alt, 
applyEquality, 
functionEquality, 
independent_isectElimination, 
independent_functionElimination, 
baseClosed, 
equalityTransitivity, 
equalitySymmetry, 
pertypeElimination, 
promote_hyp, 
productElimination, 
Error :productIsType, 
Error :equalityIstype, 
sqequalBase, 
dependent_functionElimination, 
natural_numberEquality, 
cumulativity, 
intEquality, 
voidElimination
Latex:
\mneg{}(\mforall{}[X,A:Type].  \mforall{}[E:A  {}\mrightarrow{}  A  {}\mrightarrow{}  \mBbbP{}].
        (EquivRel(A;a,b.E[a;b])
        {}\mRightarrow{}  ((X  {}\mrightarrow{}  (a,b:A//E[a;b]))  \msubseteq{}r  (f,g:X  {}\mrightarrow{}  A//fun-equiv(X;a,b.\mdownarrow{}E[a;b];f;g)))))
Date html generated:
2019_06_20-PM-00_32_59
Last ObjectModification:
2018_11_26-AM-00_13_31
Theory : quot_1
Home
Index