Nuprl Lemma : presheaf-pair-eta
∀[C:SmallCategory]. ∀[X:ps_context{j:l}(C)]. ∀[A:{X ⊢ _}]. ∀[B:{X.A ⊢ _}]. ∀[w:{X ⊢ _:Σ A B}].
  (presheaf-pair(w.1;w.2) = w ∈ {X ⊢ _:Σ A B})
Proof
Definitions occuring in Statement : 
presheaf-pair: presheaf-pair(u;v)
, 
presheaf-snd: p.2
, 
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]
, 
equal: s = t ∈ T
, 
small-category: SmallCategory
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
subtype_rel: A ⊆r B
, 
presheaf-term: {X ⊢ _:A}
, 
presheaf-pair: presheaf-pair(u;v)
, 
presheaf-sigma: Σ A B
, 
all: ∀x:A. B[x]
, 
presheaf-snd: p.2
, 
presheaf-fst: p.1
, 
implies: P 
⇒ Q
, 
pi1: fst(t)
, 
pi2: snd(t)
, 
uimplies: b supposing a
, 
and: P ∧ Q
Lemmas referenced : 
presheaf-term-equal, 
presheaf-sigma_wf, 
presheaf-pair_wf, 
ps_context_cumulativity2, 
presheaf-type-cumulativity2, 
psc-adjoin_wf, 
presheaf-fst_wf, 
presheaf-snd_wf, 
presheaf_type_at_pair_lemma, 
subtype_rel-equal, 
presheaf-type-at_wf, 
psc-adjoin-set_wf, 
I_set_wf, 
cat-ob_wf, 
presheaf-term_wf, 
presheaf-type_wf, 
small-category-cumulativity-2, 
ps_context_wf, 
small-category_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
equalitySymmetry, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
instantiate, 
applyEquality, 
because_Cache, 
sqequalRule, 
lambdaEquality_alt, 
setElimination, 
rename, 
functionExtensionality_alt, 
dependent_functionElimination, 
Error :memTop, 
independent_pairEquality, 
inhabitedIsType, 
lambdaFormation_alt, 
productElimination, 
equalityIstype, 
equalityTransitivity, 
independent_functionElimination, 
dependent_pairEquality_alt, 
independent_isectElimination, 
dependent_set_memberEquality_alt, 
independent_pairFormation, 
productIsType, 
applyLambdaEquality, 
universeIsType
Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X:ps\_context\{j:l\}(C)].  \mforall{}[A:\{X  \mvdash{}  \_\}].  \mforall{}[B:\{X.A  \mvdash{}  \_\}].  \mforall{}[w:\{X  \mvdash{}  \_:\mSigma{}  A  B\}].
    (presheaf-pair(w.1;w.2)  =  w)
Date html generated:
2020_05_20-PM-01_33_33
Last ObjectModification:
2020_04_02-PM-06_31_28
Theory : presheaf!models!of!type!theory
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