Nuprl Lemma : rtan-rminus
∀[x:{x:ℝ| x ∈ (-(π/2), π/2)} ]. (rtan(-(x)) = -(rtan(x)))
Proof
Definitions occuring in Statement : 
rtan: rtan(x)
, 
halfpi: π/2
, 
rooint: (l, u)
, 
i-member: r ∈ I
, 
req: x = y
, 
rminus: -(x)
, 
real: ℝ
, 
uall: ∀[x:A]. B[x]
, 
set: {x:A| B[x]} 
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
top: Top
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
uimplies: b supposing a
, 
prop: ℙ
, 
implies: P 
⇒ Q
, 
uiff: uiff(P;Q)
, 
req_int_terms: t1 ≡ t2
, 
false: False
, 
not: ¬A
, 
rtan: rtan(x)
, 
rneq: x ≠ y
, 
or: P ∨ Q
, 
rat_term_to_real: rat_term_to_real(f;t)
, 
rtermMinus: rtermMinus(num)
, 
rat_term_ind: rat_term_ind, 
rtermDivide: num "/" denom
, 
rtermVar: rtermVar(var)
, 
pi1: fst(t)
, 
true: True
, 
pi2: snd(t)
, 
rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced : 
member_rooint_lemma, 
istype-void, 
req_witness, 
rtan_wf, 
rminus_wf, 
rless-implies-rless, 
halfpi_wf, 
rless_wf, 
real_wf, 
i-member_wf, 
rooint_wf, 
rsub_wf, 
itermSubtract_wf, 
itermVar_wf, 
itermMinus_wf, 
req-iff-rsub-is-0, 
real_polynomial_null, 
int-to-real_wf, 
istype-int, 
real_term_value_sub_lemma, 
real_term_value_var_lemma, 
real_term_value_minus_lemma, 
real_term_value_const_lemma, 
rcos-positive, 
rdiv_wf, 
rsin_wf, 
rcos_wf, 
assert-rat-term-eq2, 
rtermDivide_wf, 
rtermMinus_wf, 
rtermVar_wf, 
req_functionality, 
rdiv_functionality, 
rsin-rminus, 
rcos-rminus, 
req_weakening
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
setElimination, 
thin, 
rename, 
sqequalHypSubstitution, 
extract_by_obid, 
dependent_functionElimination, 
isect_memberEquality_alt, 
voidElimination, 
hypothesis, 
isectElimination, 
sqequalRule, 
dependent_set_memberEquality_alt, 
hypothesisEquality, 
productElimination, 
independent_isectElimination, 
independent_pairFormation, 
because_Cache, 
productIsType, 
universeIsType, 
independent_functionElimination, 
setIsType, 
natural_numberEquality, 
approximateComputation, 
lambdaEquality_alt, 
int_eqEquality, 
inrFormation_alt
Latex:
\mforall{}[x:\{x:\mBbbR{}|  x  \mmember{}  (-(\mpi{}/2),  \mpi{}/2)\}  ].  (rtan(-(x))  =  -(rtan(x)))
Date html generated:
2019_10_30-AM-11_44_22
Last ObjectModification:
2019_04_03-AM-00_21_32
Theory : reals_2
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