Nuprl Lemma : rtan-radd-denom-positive
∀x,y:{x:ℝ| x ∈ (-(π/2), π/2)} .
(r0 < rcos(x)) ∧ (r0 < rcos(y)) ∧ (r0 < (r1 - rtan(x) * rtan(y))) supposing x + y ∈ (-(π/2), π/2)
Proof
Definitions occuring in Statement :
rtan: rtan(x),
halfpi: π/2,
rcos: rcos(x),
rooint: (l, u),
i-member: r ∈ I,
rless: x < y,
rsub: x - y,
rmul: a * b,
rminus: -(x),
radd: a + b,
int-to-real: r(n),
real: ℝ,
uimplies: b supposing a,
all: ∀x:A. B[x],
and: P ∧ Q,
set: {x:A| B[x]} ,
natural_number: $n
Definitions unfolded in proof :
all: ∀x:A. B[x],
uimplies: b supposing a,
and: P ∧ Q,
cand: A c∧ B,
member: t ∈ T,
uall: ∀[x:A]. B[x],
prop: ℙ,
so_lambda: λ2x.t[x],
so_apply: x[s],
rtan: rtan(x),
rneq: x ≠ y,
guard: {T},
or: P ∨ Q,
implies: P ⇒ Q,
iff: P ⇐⇒ Q,
rev_implies: P ⇐ Q,
uiff: uiff(P;Q),
rsub: x - y,
rdiv: (x/y),
req_int_terms: t1 ≡ t2,
false: False,
not: ¬A,
top: Top
Lemmas referenced :
rcos-positive,
radd_wf,
i-member_wf,
rooint_wf,
rminus_wf,
halfpi_wf,
set_wf,
real_wf,
int-to-real_wf,
rcos_wf,
rsub_wf,
rmul_wf,
rsin_wf,
rmul_preserves_rless,
rdiv_wf,
rless_wf,
rmul-zero-both,
rinv_wf2,
itermSubtract_wf,
itermMultiply_wf,
itermConstant_wf,
itermVar_wf,
itermAdd_wf,
itermMinus_wf,
req-iff-rsub-is-0,
rless_functionality,
req_weakening,
rcos-radd,
req_transitivity,
radd_functionality,
rminus_functionality,
rmul-rinv3,
rinv-mul-as-rdiv,
real_polynomial_null,
real_term_value_sub_lemma,
real_term_value_mul_lemma,
real_term_value_const_lemma,
real_term_value_var_lemma,
real_term_value_add_lemma,
real_term_value_minus_lemma
Rules used in proof :
sqequalSubstitution,
sqequalTransitivity,
computationStep,
sqequalReflexivity,
lambdaFormation,
isect_memberFormation,
cut,
introduction,
extract_by_obid,
sqequalHypSubstitution,
dependent_functionElimination,
thin,
hypothesisEquality,
hypothesis,
independent_pairFormation,
setElimination,
rename,
dependent_set_memberEquality,
isectElimination,
sqequalRule,
lambdaEquality,
natural_numberEquality,
because_Cache,
independent_isectElimination,
inrFormation,
independent_functionElimination,
productElimination,
approximateComputation,
int_eqEquality,
intEquality,
isect_memberEquality,
voidElimination,
voidEquality
Latex:
\mforall{}x,y:\{x:\mBbbR{}| x \mmember{} (-(\mpi{}/2), \mpi{}/2)\} .
(r0 < rcos(x)) \mwedge{} (r0 < rcos(y)) \mwedge{} (r0 < (r1 - rtan(x) * rtan(y))) supposing x + y \mmember{} (-(\mpi{}/2), \mpi{}/2)
Date html generated:
2018_05_22-PM-02_59_51
Last ObjectModification:
2017_10_19-PM-06_13_08
Theory : reals_2
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