Nuprl Lemma : context-adjoin-subset4
∀[H:j⊢]. ∀[phi:{H ⊢ _:𝔽}].
  ∀T:{H ⊢j _}. ∀[psi:{H.T ⊢ _:𝔽}]. ((psi = (phi)p ∈ {H.T ⊢ _:𝔽}) 
⇒ sub_cubical_set{j:l}(H, phi.T; H.T, psi))
Proof
Definitions occuring in Statement : 
context-subset: Gamma, phi
, 
face-type: 𝔽
, 
cc-fst: p
, 
cube-context-adjoin: X.A
, 
csm-ap-term: (t)s
, 
cubical-term: {X ⊢ _:A}
, 
cubical-type: {X ⊢ _}
, 
sub_cubical_set: Y ⊆ X
, 
cubical_set: CubicalSet
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
subtype_rel: A ⊆r B
, 
uimplies: b supposing a
, 
true: True
, 
squash: ↓T
, 
prop: ℙ
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
context-adjoin-subset3, 
csm-ap-term_wf, 
cube-context-adjoin_wf, 
face-type_wf, 
csm-face-type, 
cc-fst_wf, 
cubical-term_wf, 
cubical-type_wf, 
cubical_set_wf, 
context-subset_wf, 
subset-cubical-type, 
context-subset-is-subset, 
sub_cubical_set_wf, 
squash_wf, 
true_wf, 
iff_weakening_equal
Rules used in proof : 
cut, 
instantiate, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
lambdaFormation_alt, 
dependent_functionElimination, 
equalityIstype, 
because_Cache, 
sqequalRule, 
Error :memTop, 
universeIsType, 
applyEquality, 
independent_isectElimination, 
natural_numberEquality, 
lambdaEquality_alt, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
inhabitedIsType, 
imageMemberEquality, 
baseClosed, 
productElimination, 
independent_functionElimination
Latex:
\mforall{}[H:j\mvdash{}].  \mforall{}[phi:\{H  \mvdash{}  \_:\mBbbF{}\}].
    \mforall{}T:\{H  \mvdash{}j  \_\}.  \mforall{}[psi:\{H.T  \mvdash{}  \_:\mBbbF{}\}].  ((psi  =  (phi)p)  {}\mRightarrow{}  sub\_cubical\_set\{j:l\}(H,  phi.T;  H.T,  psi))
Date html generated:
2020_05_20-PM-03_05_08
Last ObjectModification:
2020_04_13-PM-05_49_47
Theory : cubical!type!theory
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