Nuprl Lemma : icompact-length-nonneg
∀[I:Interval]. r0 ≤ |I| supposing icompact(I)
Proof
Definitions occuring in Statement : 
icompact: icompact(I), 
i-length: |I|, 
interval: Interval, 
rleq: x ≤ y, 
int-to-real: r(n), 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
natural_number: $n
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
uimplies: b supposing a, 
icompact: icompact(I), 
and: P ∧ Q, 
i-length: |I|, 
uiff: uiff(P;Q), 
rev_uimplies: rev_uimplies(P;Q), 
rleq: x ≤ y, 
rnonneg: rnonneg(x), 
all: ∀x:A. B[x], 
le: A ≤ B, 
not: ¬A, 
implies: P ⇒ Q, 
false: False, 
subtype_rel: A ⊆r B, 
prop: ℙ, 
rsub: x - y, 
i-nonvoid: i-nonvoid(I), 
exists: ∃x:A. B[x], 
rbetween: x≤y≤z, 
guard: {T}
Lemmas referenced : 
radd-preserves-rleq, 
rsub_wf, 
right-endpoint_wf, 
left-endpoint_wf, 
less_than'_wf, 
i-length_wf, 
int-to-real_wf, 
nat_plus_wf, 
icompact_wf, 
interval_wf, 
rleq_wf, 
radd_wf, 
rminus_wf, 
uiff_transitivity, 
rleq_functionality, 
radd_comm, 
radd_functionality, 
req_weakening, 
radd-rminus-assoc, 
radd-zero-both, 
i-member-finite, 
rleq_transitivity
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalHypSubstitution, 
productElimination, 
thin, 
lemma_by_obid, 
isectElimination, 
because_Cache, 
hypothesisEquality, 
independent_isectElimination, 
hypothesis, 
sqequalRule, 
lambdaEquality, 
dependent_functionElimination, 
independent_pairEquality, 
applyEquality, 
natural_numberEquality, 
minusEquality, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
isect_memberEquality, 
voidElimination, 
independent_functionElimination
Latex:
\mforall{}[I:Interval].  r0  \mleq{}  |I|  supposing  icompact(I)
Date html generated:
2016_05_18-AM-08_46_57
Last ObjectModification:
2015_12_27-PM-11_47_38
Theory : reals
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