Nuprl Lemma : const-nonzero-on
∀[I:Interval]. ∀a:ℝ. (a ≠ r0 ⇒ a≠r0 for x ∈ I)
Proof
Definitions occuring in Statement : 
nonzero-on: f[x]≠r0 for x ∈ I, 
interval: Interval, 
rneq: x ≠ y, 
int-to-real: r(n), 
real: ℝ, 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
natural_number: $n
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
nonzero-on: f[x]≠r0 for x ∈ I, 
sq_exists: ∃x:{A| B[x]}, 
member: t ∈ T, 
and: P ∧ Q, 
cand: A c∧ B, 
uimplies: b supposing a, 
prop: ℙ, 
so_lambda: λ2x.t[x], 
so_apply: x[s]
Lemmas referenced : 
rabs_wf, 
rabs-neq-zero, 
rleq_weakening, 
req_weakening, 
i-member_wf, 
i-approx_wf, 
real_wf, 
and_wf, 
rless_wf, 
int-to-real_wf, 
all_wf, 
rleq_wf, 
set_wf, 
nat_plus_wf, 
icompact_wf, 
rneq_wf, 
interval_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
dependent_set_memberFormation, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
dependent_functionElimination, 
independent_functionElimination, 
independent_pairFormation, 
because_Cache, 
independent_isectElimination, 
setElimination, 
rename, 
natural_numberEquality, 
sqequalRule, 
lambdaEquality, 
functionEquality
Latex:
\mforall{}[I:Interval].  \mforall{}a:\mBbbR{}.  (a  \mneq{}  r0  {}\mRightarrow{}  a\mneq{}r0  for  x  \mmember{}  I)
 Date html generated: 
2016_05_18-AM-09_19_04
 Last ObjectModification: 
2015_12_27-PM-11_24_15
Theory : reals
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