Nuprl Lemma : rtan-arctangent
∀[x:ℝ]. (rtan(arctangent(x)) = x)
Proof
Definitions occuring in Statement : 
arctangent: arctangent(x)
, 
rtan: rtan(x)
, 
req: x = y
, 
real: ℝ
, 
uall: ∀[x:A]. B[x]
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
prop: ℙ
, 
uimplies: b supposing a
, 
top: Top
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
i-member: r ∈ I
, 
rooint: (l, u)
, 
implies: P 
⇒ Q
Lemmas referenced : 
arctangent-bounds, 
arctangent_one_one, 
rtan_wf, 
arctangent_wf, 
i-member_wf, 
rooint_wf, 
rminus_wf, 
halfpi_wf, 
arctangent-rtan, 
req_witness, 
member_rooint_lemma, 
rless_wf, 
real_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
dependent_set_memberEquality, 
isectElimination, 
hypothesis, 
because_Cache, 
independent_isectElimination, 
sqequalRule, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
productElimination, 
independent_pairFormation, 
productEquality, 
independent_functionElimination
Latex:
\mforall{}[x:\mBbbR{}].  (rtan(arctangent(x))  =  x)
Date html generated:
2018_05_22-PM-03_03_08
Last ObjectModification:
2017_10_22-AM-00_29_54
Theory : reals_2
Home
Index