Nuprl Lemma : pscm-adjoin-p-q
∀[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A:{X ⊢ _}]. ∀[B:{X.A ⊢ _}].  ((B)(p;q) = B ∈ {X.A ⊢ _})
Proof
Definitions occuring in Statement : 
pscm-adjoin: (s;u), 
psc-snd: q, 
psc-fst: p, 
psc-adjoin: X.A, 
pscm-ap-type: (AF)s, 
presheaf-type: {X ⊢ _}, 
ps_context: __⊢, 
uall: ∀[x:A]. B[x], 
equal: s = t ∈ T, 
small-category: SmallCategory
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
squash: ↓T, 
prop: ℙ, 
subtype_rel: A ⊆r B, 
uimplies: b supposing a, 
true: True, 
guard: {T}, 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
rev_implies: P ⇐ Q, 
implies: P ⇒ Q
Lemmas referenced : 
equal_wf, 
squash_wf, 
true_wf, 
istype-universe, 
presheaf-type_wf, 
psc-adjoin_wf, 
small-category-cumulativity-2, 
ps_context_cumulativity2, 
presheaf-type-cumulativity2, 
pscm-ap-type-is-id, 
pscm-adjoin_wf, 
psc-fst_wf, 
psc-snd_wf, 
pscm-adjoin-fst-snd, 
subtype_rel_self, 
iff_weakening_equal, 
ps_context_wf, 
small-category_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
applyEquality, 
thin, 
instantiate, 
lambdaEquality_alt, 
sqequalHypSubstitution, 
imageElimination, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
universeIsType, 
universeEquality, 
sqequalRule, 
because_Cache, 
independent_isectElimination, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
productElimination, 
independent_functionElimination, 
isect_memberEquality_alt, 
axiomEquality, 
isectIsTypeImplies, 
inhabitedIsType
Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X:ps\_context\{j:l\}(C)].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[B:\{X.A  \mvdash{}  \_\}].    ((B)(p;q)  =  B)
Date html generated:
2020_05_20-PM-01_28_34
Last ObjectModification:
2020_04_02-PM-01_56_17
Theory : presheaf!models!of!type!theory
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