Nuprl Lemma : fiber-comp-exists
∀X:j⊢. ∀T,A:{X ⊢ _}. ∀w:{X ⊢ _:(T ⟶ A)}. ∀a:{X ⊢ _:A}.  (X ⊢ CompOp(T) 
⇒ X ⊢ CompOp(A) 
⇒ X ⊢ CompOp(Fiber(w;a)))
Proof
Definitions occuring in Statement : 
composition-op: Gamma ⊢ CompOp(A)
, 
cubical-fiber: Fiber(w;a)
, 
cubical-fun: (A ⟶ B)
, 
cubical-term: {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 : 
composition-op-implies-composition-structure, 
composition-structure-implies-composition-op, 
cubical-fiber_wf, 
fiber-comp_wf, 
composition-op_wf, 
cubical_set_cumulativity-i-j, 
cubical-type-cumulativity2, 
istype-cubical-term, 
cubical-fun_wf, 
cubical-type_wf, 
cubical_set_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
rename, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
instantiate, 
because_Cache, 
isectElimination, 
hypothesis, 
independent_functionElimination, 
universeIsType, 
applyEquality, 
sqequalRule, 
inhabitedIsType
Latex:
\mforall{}X:j\mvdash{}.  \mforall{}T,A:\{X  \mvdash{}  \_\}.  \mforall{}w:\{X  \mvdash{}  \_:(T  {}\mrightarrow{}  A)\}.  \mforall{}a:\{X  \mvdash{}  \_:A\}.
    (X  \mvdash{}  CompOp(T)  {}\mRightarrow{}  X  \mvdash{}  CompOp(A)  {}\mRightarrow{}  X  \mvdash{}  CompOp(Fiber(w;a)))
Date html generated:
2020_05_20-PM-05_13_21
Last ObjectModification:
2020_04_18-PM-00_02_16
Theory : cubical!type!theory
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