Nuprl Lemma : discrete-fun-bijection
∀[A,B:Type].  Bij({() ⊢ _:(discr(A) ⟶ discr(B))};{() ⊢ _:discr(A ⟶ B)};λf.discrete-fun(f))
Proof
Definitions occuring in Statement : 
discrete-fun: discrete-fun(f)
, 
discrete-cubical-type: discr(T)
, 
cubical-fun: (A ⟶ B)
, 
cubical-term: {X ⊢ _:A}
, 
trivial-cube-set: ()
, 
biject: Bij(A;B;f)
, 
uall: ∀[x:A]. B[x]
, 
lambda: λx.A[x]
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
biject: Bij(A;B;f)
, 
and: P ∧ Q
, 
inject: Inj(A;B;f)
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
prop: ℙ
, 
surject: Surj(A;B;f)
, 
cubical-term-at: u(a)
, 
uimplies: b supposing a
, 
discrete-cubical-type: discr(T)
, 
cubical-fun: (A ⟶ B)
, 
top: Top
, 
cubical-fun-family: cubical-fun-family(X; A; B; I; a)
, 
squash: ↓T
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
discrete-fun: discrete-fun(f)
, 
true: True
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
exists: ∃x:A. B[x]
, 
cubical-term: {X ⊢ _:A}
, 
cc-snd: q
, 
cube-context-adjoin: X.A
, 
pi1: fst(t)
, 
pi2: snd(t)
, 
cubical-lam: cubical-lam(X;b)
, 
cubical-lambda: (λb)
, 
cc-adjoin-cube: (v;u)
Lemmas referenced : 
equal_wf, 
cubical-term_wf, 
trivial-cube-set_wf, 
discrete-cubical-type_wf, 
discrete-fun_wf, 
cubical-fun_wf, 
I_cube_wf, 
fset_wf, 
nat_wf, 
cubical-term-equal, 
cubical-term-at_wf, 
cubical_type_at_pair_lemma, 
cubical_type_ap_morph_pair_lemma, 
all_wf, 
names-hom_wf, 
nh-comp_wf, 
squash_wf, 
true_wf, 
cubical-type-at_wf, 
nh-id_wf, 
nh-id-right, 
iff_weakening_equal, 
cubical-lam_wf, 
csm-discrete-cubical-type, 
I_cube_pair_redex_lemma, 
pi1_wf_top, 
pi2_wf, 
cube_set_restriction_pair_lemma, 
cube-set-restriction_wf, 
cube-context-adjoin_wf, 
cubical-type-ap-morph_wf, 
cube-set-restriction-id
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
independent_pairFormation, 
lambdaFormation, 
sqequalRule, 
cut, 
hypothesis, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
functionEquality, 
cumulativity, 
hypothesisEquality, 
universeEquality, 
rename, 
functionExtensionality, 
equalityTransitivity, 
equalitySymmetry, 
independent_isectElimination, 
dependent_functionElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
applyLambdaEquality, 
setElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
dependent_set_memberEquality, 
lambdaEquality, 
because_Cache, 
applyEquality, 
hyp_replacement, 
natural_numberEquality, 
independent_functionElimination, 
productElimination, 
dependent_pairFormation, 
independent_pairEquality, 
productEquality
Latex:
\mforall{}[A,B:Type].    Bij(\{()  \mvdash{}  \_:(discr(A)  {}\mrightarrow{}  discr(B))\};\{()  \mvdash{}  \_:discr(A  {}\mrightarrow{}  B)\};\mlambda{}f.discrete-fun(f))
Date html generated:
2017_10_05-AM-02_12_38
Last ObjectModification:
2017_03_02-PM-11_22_08
Theory : cubical!type!theory
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