Nuprl Lemma : rsin-rsub
∀[x,y:ℝ].  (rsin(x - y) = ((rsin(x) * rcos(y)) - rcos(x) * rsin(y)))
Proof
Definitions occuring in Statement : 
rcos: rcos(x)
, 
rsin: rsin(x)
, 
rsub: x - y
, 
req: x = y
, 
rmul: a * b
, 
real: ℝ
, 
uall: ∀[x:A]. B[x]
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
rsub: x - y
, 
implies: P 
⇒ Q
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
all: ∀x:A. B[x]
, 
rev_uimplies: rev_uimplies(P;Q)
, 
req_int_terms: t1 ≡ t2
, 
false: False
, 
not: ¬A
, 
top: Top
Lemmas referenced : 
req_witness, 
rsin_wf, 
rsub_wf, 
rmul_wf, 
rcos_wf, 
real_wf, 
radd_wf, 
rminus_wf, 
itermSubtract_wf, 
itermAdd_wf, 
itermMultiply_wf, 
itermVar_wf, 
itermMinus_wf, 
req-iff-rsub-is-0, 
req_functionality, 
req_transitivity, 
rsin-radd, 
radd_functionality, 
rmul_functionality, 
req_weakening, 
rsin-rminus, 
rcos-rminus, 
real_polynomial_null, 
int-to-real_wf, 
istype-int, 
real_term_value_sub_lemma, 
istype-void, 
real_term_value_add_lemma, 
real_term_value_mul_lemma, 
real_term_value_var_lemma, 
real_term_value_minus_lemma, 
real_term_value_const_lemma
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
independent_functionElimination, 
inhabitedIsType, 
sqequalRule, 
isect_memberEquality_alt, 
because_Cache, 
isectIsTypeImplies, 
universeIsType, 
natural_numberEquality, 
productElimination, 
independent_isectElimination, 
dependent_functionElimination, 
approximateComputation, 
lambdaEquality_alt, 
int_eqEquality, 
voidElimination
Latex:
\mforall{}[x,y:\mBbbR{}].    (rsin(x  -  y)  =  ((rsin(x)  *  rcos(y))  -  rcos(x)  *  rsin(y)))
Date html generated:
2019_10_30-AM-11_41_48
Last ObjectModification:
2019_05_17-AM-11_26_30
Theory : reals_2
Home
Index