Nuprl Lemma : nh-comp-is-id
∀[I,J:fset(ℕ)].
  ∀[f:I ⟶ J]. ∀[g:J ⟶ I].
    g ⋅ f = 1 ∈ I ⟶ I supposing ∀x:names(I). (((g x) = <x> ∈ Point(dM(J))) ∧ ((f x) = <x> ∈ Point(dM(I)))) 
  supposing I ⊆ J
Proof
Definitions occuring in Statement : 
nh-comp: g ⋅ f, 
nh-id: 1, 
names-hom: I ⟶ J, 
dM_inc: <x>, 
dM: dM(I), 
names: names(I), 
lattice-point: Point(l), 
f-subset: xs ⊆ ys, 
fset: fset(T), 
int-deq: IntDeq, 
nat: ℕ, 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
and: P ∧ Q, 
apply: f a, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
uimplies: b supposing a, 
names-hom: I ⟶ J, 
nh-id: 1, 
nh-comp: g ⋅ f, 
dma-lift-compose: dma-lift-compose(I;J;eqi;eqj;f;g), 
compose: f o g, 
dM: dM(I), 
dM-lift: dM-lift(I;J;f), 
prop: ℙ, 
so_lambda: λ2x.t[x], 
and: P ∧ Q, 
subtype_rel: A ⊆r B, 
DeMorgan-algebra: DeMorganAlgebra, 
guard: {T}, 
so_apply: x[s], 
nat: ℕ, 
squash: ↓T, 
dma-hom: dma-hom(dma1;dma2), 
bounded-lattice-hom: Hom(l1;l2), 
lattice-hom: Hom(l1;l2), 
all: ∀x:A. B[x], 
true: True, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q, 
implies: P ⇒ Q
Lemmas referenced : 
names_wf, 
all_wf, 
equal_wf, 
lattice-point_wf, 
dM_wf, 
subtype_rel_set, 
DeMorgan-algebra-structure_wf, 
lattice-structure_wf, 
lattice-axioms_wf, 
bounded-lattice-structure-subtype, 
DeMorgan-algebra-structure-subtype, 
subtype_rel_transitivity, 
bounded-lattice-structure_wf, 
bounded-lattice-axioms_wf, 
uall_wf, 
lattice-meet_wf, 
lattice-join_wf, 
DeMorgan-algebra-axioms_wf, 
dM_inc_wf, 
names-subtype, 
names-hom_wf, 
f-subset_wf, 
nat_wf, 
int-deq_wf, 
strong-subtype-deq-subtype, 
strong-subtype-set3, 
le_wf, 
strong-subtype-self, 
fset_wf, 
squash_wf, 
true_wf, 
dM-lift_wf, 
dma-hom_wf, 
iff_weakening_equal, 
dM-lift-is-id
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
functionExtensionality, 
sqequalRule, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
lambdaEquality, 
productEquality, 
applyEquality, 
instantiate, 
independent_isectElimination, 
cumulativity, 
universeEquality, 
because_Cache, 
isect_memberEquality, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
intEquality, 
natural_numberEquality, 
imageElimination, 
setElimination, 
rename, 
setEquality, 
dependent_functionElimination, 
productElimination, 
imageMemberEquality, 
baseClosed, 
independent_functionElimination, 
dependent_set_memberEquality, 
lambdaFormation
Latex:
\mforall{}[I,J:fset(\mBbbN{})].
    \mforall{}[f:I  {}\mrightarrow{}  J].  \mforall{}[g:J  {}\mrightarrow{}  I].    g  \mcdot{}  f  =  1  supposing  \mforall{}x:names(I).  (((g  x)  =  <x>)  \mwedge{}  ((f  x)  =  <x>)) 
    supposing  I  \msubseteq{}  J
Date html generated:
2017_10_05-AM-01_01_53
Last ObjectModification:
2017_07_28-AM-09_26_00
Theory : cubical!type!theory
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