Nuprl Lemma : sigma-path-fst

∀X:j⊢. ∀A:{X ⊢ _}. ∀B:{X.A ⊢ _}. ∀x,y:{X ⊢ _:Σ A B}.  ({X ⊢ _:(Path_Σ A B x y)} ⇒ {X ⊢ _:(Path_A x.1 y.1)})


Proof




Definitions occuring in Statement :  path-type: (Path_A a b),  cubical-fst: p.1,  cubical-sigma: Σ A B,  cube-context-adjoin: X.A,  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,  and: P ∧ Q,  cubical-type: {X ⊢ _},  cc-snd: q,  cc-fst: p,  csm-ap-type: (AF)s,  interval-type: 𝕀,  csm-comp: G o F,  csm-ap: (s)x,  constant-cubical-type: (X),  compose: f o g,  uimplies: b supposing a,  cubical-path-app: pth @ r,  true: True,  same-cubical-term: X ⊢ u=v:A,  squash: ↓T,  prop: ℙ,  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  cubical-term_wf,  path-type_wf,  cubical-sigma_wf,  cubical-type-cumulativity2,  cubical_set_cumulativity-i-j,  cube-context-adjoin_wf,  cubical-type_wf,  cubical_set_wf,  path-eta_wf,  path-type-subtype,  cubical-sigma-p,  interval-type_wf,  term-to-path-wf,  cubical-fst_wf,  csm-ap-type_wf,  cc-fst_wf,  csm-adjoin_wf,  csm-comp_wf,  cc-snd_wf,  csm-cubical-fst,  path-eta-1,  path-eta-0,  same-cubical-term_wf,  squash_wf,  true_wf,  cubical-path-app-1,  iff_weakening_equal,  cubical-path-app-0
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  universeIsType,  cut,  thin,  instantiate,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  applyEquality,  hypothesis,  sqequalRule,  inhabitedIsType,  because_Cache,  rename,  dependent_functionElimination,  equalitySymmetry,  dependent_set_memberEquality_alt,  independent_pairFormation,  equalityTransitivity,  productIsType,  equalityIstype,  applyLambdaEquality,  setElimination,  productElimination,  lambdaEquality_alt,  hyp_replacement,  independent_isectElimination,  Error :memTop,  natural_numberEquality,  imageElimination,  imageMemberEquality,  baseClosed,  independent_functionElimination

Latex:
\mforall{}X:j\mvdash{}.  \mforall{}A:\{X  \mvdash{}  \_\}.  \mforall{}B:\{X.A  \mvdash{}  \_\}.  \mforall{}x,y:\{X  \mvdash{}  \_:\mSigma{}  A  B\}.
    (\{X  \mvdash{}  \_:(Path\_\mSigma{}  A  B  x  y)\}  {}\mRightarrow{}  \{X  \mvdash{}  \_:(Path\_A  x.1  y.1)\})



Date html generated: 2020_05_20-PM-03_25_06
Last ObjectModification: 2020_04_07-PM-04_41_22

Theory : cubical!type!theory


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