Nuprl Lemma : sigma-comp-exists
∀Gamma:j⊢. ∀A:{Gamma ⊢ _}. ∀B:{Gamma.A ⊢ _}.  (Gamma ⊢ CompOp(A) 
⇒ Gamma.A ⊢ CompOp(B) 
⇒ Gamma ⊢ CompOp(Σ A B))
Proof
Definitions occuring in Statement : 
composition-op: Gamma ⊢ CompOp(A)
, 
cubical-sigma: Σ A B
, 
cube-context-adjoin: X.A
, 
cubical-type: {X ⊢ _}
, 
cubical_set: CubicalSet
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
subtype_rel: A ⊆r B
Lemmas referenced : 
sigmacomp_wf, 
cubical-type-cumulativity2, 
cubical_set_cumulativity-i-j, 
cube-context-adjoin_wf, 
composition-op_wf, 
cubical-type_wf, 
cubical_set_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
rename, 
introduction, 
cut, 
thin, 
instantiate, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
applyEquality, 
because_Cache, 
hypothesis, 
sqequalRule, 
universeIsType
Latex:
\mforall{}Gamma:j\mvdash{}.  \mforall{}A:\{Gamma  \mvdash{}  \_\}.  \mforall{}B:\{Gamma.A  \mvdash{}  \_\}.
    (Gamma  \mvdash{}  CompOp(A)  {}\mRightarrow{}  Gamma.A  \mvdash{}  CompOp(B)  {}\mRightarrow{}  Gamma  \mvdash{}  CompOp(\mSigma{}  A  B))
Date html generated:
2020_05_20-PM-04_06_32
Last ObjectModification:
2020_04_10-AM-03_42_27
Theory : cubical!type!theory
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