Nuprl Lemma : rtan_wf
∀x:{x:ℝ| x ∈ (-(π/2), π/2)} . (rtan(x) ∈ ℝ)
Proof
Definitions occuring in Statement : 
rtan: rtan(x)
, 
halfpi: π/2
, 
rooint: (l, u)
, 
i-member: r ∈ I
, 
rminus: -(x)
, 
real: ℝ
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
set: {x:A| B[x]} 
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
rtan: rtan(x)
, 
uall: ∀[x:A]. B[x]
, 
uimplies: b supposing a
, 
rneq: x ≠ y
, 
guard: {T}
, 
or: P ∨ Q
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
Lemmas referenced : 
rcos-positive, 
rdiv_wf, 
rsin_wf, 
rcos_wf, 
rless_wf, 
int-to-real_wf, 
set_wf, 
real_wf, 
i-member_wf, 
rooint_wf, 
rminus_wf, 
halfpi_wf
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
hypothesis, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
setElimination, 
rename, 
sqequalRule, 
isectElimination, 
because_Cache, 
independent_isectElimination, 
inrFormation, 
natural_numberEquality, 
lambdaEquality
Latex:
\mforall{}x:\{x:\mBbbR{}|  x  \mmember{}  (-(\mpi{}/2),  \mpi{}/2)\}  .  (rtan(x)  \mmember{}  \mBbbR{})
Date html generated:
2018_05_22-PM-02_59_16
Last ObjectModification:
2017_10_19-PM-05_19_05
Theory : reals_2
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