Nuprl Lemma : period-rcos-is-2pi
∀a:ℝ. ((r0 < a) 
⇒ (∀x:ℝ. (rcos(x + a) = rcos(x))) 
⇒ (2 * π ≤ a))
Proof
Definitions occuring in Statement : 
pi: π
, 
rcos: rcos(x)
, 
rleq: x ≤ y
, 
rless: x < y
, 
int-rmul: k1 * a
, 
req: x = y
, 
radd: a + b
, 
int-to-real: r(n)
, 
real: ℝ
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
natural_number: $n
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
uimplies: b supposing a
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
rev_uimplies: rev_uimplies(P;Q)
, 
guard: {T}
Lemmas referenced : 
period-rsin-is-2pi, 
real_wf, 
all_wf, 
req_wf, 
rcos_wf, 
radd_wf, 
rless_wf, 
int-to-real_wf, 
rminus_wf, 
rsin_wf, 
halfpi_wf, 
req_functionality, 
req_inversion, 
rcos-shift-half-pi, 
req_weakening, 
uiff_transitivity, 
radd-assoc, 
req_transitivity, 
radd-ac, 
radd_functionality, 
radd_comm, 
rcos_functionality, 
radd-preserves-req, 
rminus_functionality, 
rsin_functionality, 
radd-rminus-assoc, 
radd-rminus-both, 
radd-zero-both
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
independent_functionElimination, 
hypothesis, 
isectElimination, 
sqequalRule, 
lambdaEquality, 
natural_numberEquality, 
independent_isectElimination, 
productElimination, 
because_Cache
Latex:
\mforall{}a:\mBbbR{}.  ((r0  <  a)  {}\mRightarrow{}  (\mforall{}x:\mBbbR{}.  (rcos(x  +  a)  =  rcos(x)))  {}\mRightarrow{}  (2  *  \mpi{}  \mleq{}  a))
Date html generated:
2016_10_26-PM-00_26_59
Last ObjectModification:
2016_09_12-PM-05_44_08
Theory : reals_2
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