Nuprl Lemma : presheaf-subset-and
∀[C:SmallCategory]. ∀[F:presheaf{j:l}(C)]. ∀[P,Q:I:cat-ob(C) ⟶ (F I) ⟶ ℙ].
  ext-equal-presheaves(C;F|I,rho.P[I;rho]|I,rho.Q[I;rho];F|I,rho.P[I;rho] ∧ Q[I;rho]) 
  supposing stable-element-predicate(C;F;I,rho.P[I;rho]) ∧ stable-element-predicate(C;F;I,rho.Q[I;rho])
Proof
Definitions occuring in Statement : 
presheaf-subset: F|I,rho.P[I; rho], 
stable-element-predicate: stable-element-predicate(C;F;I,rho.P[I; rho]), 
ext-equal-presheaves: ext-equal-presheaves(C;F;G), 
presheaf: Presheaf(C), 
functor-ob: ob(F), 
cat-ob: cat-ob(C), 
small-category: SmallCategory, 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
so_apply: x[s1;s2], 
and: P ∧ Q, 
apply: f a, 
function: x:A ⟶ B[x]
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
uimplies: b supposing a, 
and: P ∧ Q, 
ext-equal-presheaves: ext-equal-presheaves(C;F;G), 
all: ∀x:A. B[x], 
presheaf-subset: F|I,rho.P[I; rho], 
mk-presheaf: mk-presheaf, 
so_lambda: so_lambda3, 
so_apply: x[s1;s2;s3], 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
ext-eq: A ≡ B, 
subtype_rel: A ⊆r B, 
so_lambda: λ2x y.t[x; y], 
prop: ℙ, 
so_apply: x[s1;s2], 
presheaf: Presheaf(C), 
cat-ob: cat-ob(C), 
pi1: fst(t), 
type-cat: TypeCat, 
guard: {T}, 
stable-element-predicate: stable-element-predicate(C;F;I,rho.P[I; rho]), 
implies: P ⇒ Q
Lemmas referenced : 
small-category_wf, 
ob_mk_functor_lemma, 
arrow_mk_functor_lemma, 
cat-arrow_wf, 
stable-element-predicate_wf, 
small-category-cumulativity-2, 
presheaf-cumulativity1, 
functor-ob_wf, 
op-cat_wf, 
type-cat_wf, 
subtype_rel-equal, 
cat-ob_wf, 
cat_ob_op_lemma, 
subtype_rel_self, 
cat_ob_pair_lemma, 
functor-arrow_wf, 
op-cat-arrow, 
presheaf_wf1
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
universeIsType, 
cut, 
introduction, 
extract_by_obid, 
hypothesis, 
sqequalHypSubstitution, 
productElimination, 
thin, 
independent_pairFormation, 
lambdaFormation_alt, 
sqequalRule, 
dependent_functionElimination, 
Error :memTop, 
because_Cache, 
applyEquality, 
isectElimination, 
hypothesisEquality, 
independent_pairEquality, 
lambdaEquality_alt, 
axiomEquality, 
functionIsTypeImplies, 
inhabitedIsType, 
productIsType, 
instantiate, 
cumulativity, 
independent_isectElimination, 
universeEquality, 
isect_memberEquality_alt, 
isectIsTypeImplies, 
functionIsType, 
setElimination, 
rename, 
dependent_set_memberEquality_alt, 
setIsType, 
functionExtensionality, 
setEquality, 
independent_functionElimination
Latex:
\mforall{}[C:SmallCategory].  \mforall{}[F:presheaf\{j:l\}(C)].  \mforall{}[P,Q:I:cat-ob(C)  {}\mrightarrow{}  (F  I)  {}\mrightarrow{}  \mBbbP{}].
    ext-equal-presheaves(C;F|I,rho.P[I;rho]|I,rho.Q[I;rho];F|I,rho.P[I;rho]  \mwedge{}  Q[I;rho]) 
    supposing  stable-element-predicate(C;F;I,rho.P[I;rho])
    \mwedge{}  stable-element-predicate(C;F;I,rho.Q[I;rho])
Date html generated:
2020_05_20-AM-07_57_39
Last ObjectModification:
2020_04_02-AM-09_48_25
Theory : small!categories
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