Nuprl Lemma : no-retraction-case-0
∀[k:ℕ]. ∀[K:0-dim-complex].  (0 < ||K|| ⇒ (¬retraction(|K|;rn-prod-metric(k);|∂(K)|)))
Proof
Definitions occuring in Statement : 
rat-cube-complex-polyhedron: |K|, 
rn-prod-metric: rn-prod-metric(n), 
retraction: retraction(X;d;A), 
length: ||as||, 
nat: ℕ, 
less_than: a < b, 
uall: ∀[x:A]. B[x], 
not: ¬A, 
implies: P ⇒ Q, 
natural_number: $n, 
rat-complex-boundary: ∂(K), 
rational-cube-complex: n-dim-complex
Definitions unfolded in proof : 
retraction: retraction(X;d;A), 
so_apply: x[s], 
so_lambda: λ2x.t[x], 
prop: ℙ, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
ge: i ≥ j , 
lelt: i ≤ j < k, 
int_seg: {i..j-}, 
so_apply: x[s1;s2], 
top: Top, 
so_lambda: λ2x y.t[x; y], 
it: ⋅, 
nil: [], 
all: ∀x:A. B[x], 
uimplies: b supposing a, 
select: L[n], 
exists: ∃x:A. B[x], 
l_exists: (∃x∈L. P[x]), 
subtype_rel: A ⊆r B, 
false: False, 
not: ¬A, 
less_than': less_than'(a;b), 
and: P ∧ Q, 
le: A ≤ B, 
nat: ℕ, 
rational-cube-complex: n-dim-complex, 
rat-cube-complex-polyhedron: |K|, 
member: t ∈ T, 
implies: P ⇒ Q, 
uall: ∀[x:A]. B[x]
Lemmas referenced : 
int_seg_wf, 
exists_wf, 
subtype_rel_sets_simple, 
metric-on-subtype, 
rn-prod-metric_wf, 
in-rat-cube_wf, 
not_wf, 
rat-cube-complex-polyhedron_wf, 
retraction_wf, 
member-not, 
rat-cube-complex-polyhedron-inhabited, 
l_exists_wf_nil, 
real-vec_wf, 
int_formula_prop_wf, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_term_value_var_lemma, 
int_formula_prop_less_lemma, 
int_formula_prop_and_lemma, 
istype-int, 
intformle_wf, 
itermConstant_wf, 
itermVar_wf, 
intformless_wf, 
intformand_wf, 
full-omega-unsat, 
nat_properties, 
int_seg_properties, 
length_of_nil_lemma, 
istype-base, 
stuck-spread, 
istype-nat, 
istype-le, 
istype-void, 
rational-cube-complex_wf, 
rational-cube_wf, 
length_wf, 
istype-less_than, 
rat-complex-boundary-0-dim
Rules used in proof : 
productIsType, 
promote_hyp, 
closedConclusion, 
applyEquality, 
setEquality, 
functionIsType, 
setIsType, 
because_Cache, 
dependent_functionElimination, 
int_eqEquality, 
dependent_pairFormation_alt, 
approximateComputation, 
isect_memberEquality_alt, 
independent_isectElimination, 
baseClosed, 
productElimination, 
independent_functionElimination, 
lambdaEquality_alt, 
voidElimination, 
sqequalRule, 
independent_pairFormation, 
dependent_set_memberEquality_alt, 
universeIsType, 
rename, 
setElimination, 
natural_numberEquality, 
hypothesis, 
hypothesisEquality, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
cut, 
introduction, 
lambdaFormation_alt, 
isect_memberFormation_alt, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}[k:\mBbbN{}].  \mforall{}[K:0-dim-complex].    (0  <  ||K||  {}\mRightarrow{}  (\mneg{}retraction(|K|;rn-prod-metric(k);|\mpartial{}(K)|)))
Date html generated:
2019_10_30-AM-10_13_27
Last ObjectModification:
2019_10_29-PM-01_34_03
Theory : real!vectors
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