Nuprl Lemma : presheaf-fst-pair
∀[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A:{X ⊢ _}]. ∀[u:{X ⊢ _:A}]. ∀[v:Top].
  (presheaf-pair(u;v).1 = u ∈ {X ⊢ _:A})
Proof
Definitions occuring in Statement : 
presheaf-pair: presheaf-pair(u;v)
, 
presheaf-fst: p.1
, 
presheaf-term: {X ⊢ _:A}
, 
presheaf-type: {X ⊢ _}
, 
ps_context: __⊢
, 
uall: ∀[x:A]. B[x]
, 
top: Top
, 
equal: s = t ∈ T
, 
small-category: SmallCategory
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
presheaf-fst: p.1
, 
pi1: fst(t)
, 
presheaf-pair: presheaf-pair(u;v)
, 
presheaf-term: {X ⊢ _:A}
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
Lemmas referenced : 
I_set_wf, 
cat-ob_wf, 
presheaf-term-equal, 
istype-top, 
presheaf-term_wf, 
presheaf-type_wf, 
ps_context_wf, 
small-category-cumulativity-2, 
small-category_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
equalitySymmetry, 
functionExtensionality, 
sqequalRule, 
hypothesis, 
applyEquality, 
sqequalHypSubstitution, 
setElimination, 
thin, 
rename, 
hypothesisEquality, 
extract_by_obid, 
isectElimination, 
equalityTransitivity, 
independent_isectElimination, 
isect_memberEquality_alt, 
axiomEquality, 
isectIsTypeImplies, 
inhabitedIsType, 
universeIsType, 
instantiate
Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X:ps\_context\{j:l\}(C)].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[u:\{X  \mvdash{}  \_:A\}].  \mforall{}[v:Top].
    (presheaf-pair(u;v).1  =  u)
Date html generated:
2020_05_20-PM-01_33_30
Last ObjectModification:
2020_04_02-PM-06_31_19
Theory : presheaf!models!of!type!theory
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