Nuprl Lemma : presheaf-fst_wf
∀[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A:{X ⊢ _}]. ∀[B:{X.A ⊢ _}]. ∀[p:{X ⊢ _:Σ A B}].  (p.1 ∈ {X ⊢ _:A})
Proof
Definitions occuring in Statement : 
presheaf-fst: p.1
, 
presheaf-sigma: Σ A B
, 
psc-adjoin: X.A
, 
presheaf-term: {X ⊢ _:A}
, 
presheaf-type: {X ⊢ _}
, 
ps_context: __⊢
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
small-category: SmallCategory
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
presheaf-fst: p.1
, 
presheaf-term: {X ⊢ _:A}
, 
subtype_rel: A ⊆r B
, 
presheaf-sigma: Σ A B
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
pi1: fst(t)
, 
presheaf-type: {X ⊢ _}
, 
and: P ∧ Q
, 
presheaf-type-ap-morph: (u a f)
, 
presheaf-type-at: A(a)
, 
pi2: snd(t)
, 
prop: ℙ
Lemmas referenced : 
presheaf-term_wf, 
presheaf-sigma_wf, 
presheaf-type_wf, 
psc-adjoin_wf, 
small-category-cumulativity-2, 
ps_context_cumulativity2, 
presheaf-type-cumulativity2, 
ps_context_wf, 
small-category_wf, 
presheaf_type_at_pair_lemma, 
I_set_wf, 
cat-ob_wf, 
presheaf_type_ap_morph_pair_lemma, 
cat-arrow_wf, 
equal_wf, 
psc-restriction_wf, 
pi1_wf_top
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
sqequalRule, 
sqequalHypSubstitution, 
setElimination, 
thin, 
rename, 
dependent_set_memberEquality_alt, 
hypothesis, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
universeIsType, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
isect_memberEquality_alt, 
isectIsTypeImplies, 
inhabitedIsType, 
instantiate, 
applyEquality, 
dependent_functionElimination, 
Error :memTop, 
lambdaEquality_alt, 
lambdaFormation_alt, 
productElimination, 
equalityIstype, 
independent_functionElimination, 
hyp_replacement, 
applyLambdaEquality, 
because_Cache, 
independent_pairEquality, 
functionIsType
Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X:ps\_context\{j:l\}(C)].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[B:\{X.A  \mvdash{}  \_\}].  \mforall{}[p:\{X  \mvdash{}  \_:\mSigma{}  A  B\}].
    (p.1  \mmember{}  \{X  \mvdash{}  \_:A\})
Date html generated:
2020_05_20-PM-01_31_43
Last ObjectModification:
2020_04_02-PM-03_04_38
Theory : presheaf!models!of!type!theory
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