Nuprl Lemma : rabs-rcos-rleq
∀x:ℝ. (|rcos(x)| ≤ r1)
Proof
Definitions occuring in Statement : 
rcos: rcos(x)
, 
rleq: x ≤ y
, 
rabs: |x|
, 
int-to-real: r(n)
, 
real: ℝ
, 
all: ∀x:A. B[x]
, 
natural_number: $n
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
uimplies: b supposing a
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced : 
real_wf, 
rabs_wf, 
rcos_wf, 
cosine_wf, 
int-to-real_wf, 
rabs-cosine-rleq, 
rleq_functionality, 
rabs_functionality, 
rcos-is-cosine, 
req_weakening
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
natural_numberEquality, 
because_Cache, 
dependent_functionElimination, 
independent_isectElimination, 
productElimination
Latex:
\mforall{}x:\mBbbR{}.  (|rcos(x)|  \mleq{}  r1)
Date html generated:
2016_10_26-PM-00_15_00
Last ObjectModification:
2016_09_12-PM-05_40_42
Theory : reals_2
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