Nuprl Lemma : bij-contr_wf

X:j⊢. ∀A,B:{X ⊢ _}. ∀f:{X ⊢ _:(A ⟶ B)}. ∀g:{X ⊢ _:(B ⟶ A)}. ∀cA:X +⊢ Compositon(A).
b:{X.A ⊢ _:(Path_(A)p app((g)p; app((f)p; q)) q)}. ∀c:{X ⊢ _:Contractible(B)}.
  (bij-contr(X; A; f; g; cA; b; c) ∈ {X ⊢ _:Contractible(A)})


Proof




Definitions occuring in Statement :  bij-contr: bij-contr(X; A; f; g; cA; b; c) composition-structure: Gamma ⊢ Compositon(A) contractible-type: Contractible(A) path-type: (Path_A b) cubical-app: app(w; u) cubical-fun: (A ⟶ B) cc-snd: q cc-fst: p cube-context-adjoin: X.A csm-ap-term: (t)s cubical-term: {X ⊢ _:A} csm-ap-type: (AF)s cubical-type: {X ⊢ _} cubical_set: CubicalSet all: x:A. B[x] member: t ∈ T
Definitions unfolded in proof :  all: x:A. B[x] member: t ∈ T uall: [x:A]. B[x] subtype_rel: A ⊆B uimplies: supposing a bij-contr: bij-contr(X; A; f; g; cA; b; c) squash: T prop: true: True
Lemmas referenced :  csm-cubical-fun cc-fst_wf cubical-type-cumulativity2 cubical-term-eqcd csm-ap-term_wf cube-context-adjoin_wf cubical-fun_wf cubical_set_cumulativity-i-j cubical-app_wf_fun contr-center_wf contr-witness_wf comp_path_wf csm-comp-structure_wf csm-ap-type_wf istype-cubical-term contractible-type_wf path-type_wf cc-snd_wf composition-structure_wf cubical-type_wf cubical_set_wf map-path_wf contr-path_wf csm-contractible-type squash_wf true_wf csm-contr-center csm-ap-cubical-app-fun
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation_alt cut thin instantiate introduction extract_by_obid sqequalHypSubstitution dependent_functionElimination because_Cache hypothesisEquality isectElimination applyEquality hypothesis sqequalRule equalityTransitivity equalitySymmetry independent_isectElimination lambdaEquality_alt hyp_replacement universeIsType imageElimination inhabitedIsType natural_numberEquality imageMemberEquality baseClosed Error :memTop

Latex:
\mforall{}X:j\mvdash{}.  \mforall{}A,B:\{X  \mvdash{}  \_\}.  \mforall{}f:\{X  \mvdash{}  \_:(A  {}\mrightarrow{}  B)\}.  \mforall{}g:\{X  \mvdash{}  \_:(B  {}\mrightarrow{}  A)\}.  \mforall{}cA:X  +\mvdash{}  Compositon(A).
\mforall{}b:\{X.A  \mvdash{}  \_:(Path\_(A)p  app((g)p;  app((f)p;  q))  q)\}.  \mforall{}c:\{X  \mvdash{}  \_:Contractible(B)\}.
    (bij-contr(X;  A;  f;  g;  cA;  b;  c)  \mmember{}  \{X  \mvdash{}  \_:Contractible(A)\})



Date html generated: 2020_05_20-PM-05_24_50
Last ObjectModification: 2020_04_20-PM-02_17_58

Theory : cubical!type!theory


Home Index