Nuprl Lemma : derivative-function-rsub-const
∀f,f':ℝ ⟶ ℝ.
  ((∀x,y:ℝ.  ((x = y) ⇒ (f'[x] = f'[y])))
  ⇒ d(f[x])/dx = λx.f'[x] on (-∞, ∞)
  ⇒ (∀y:ℝ. d(f[x - y])/dx = λx.f'[x - y] on (-∞, ∞)))
Proof
Definitions occuring in Statement : 
derivative: d(f[x])/dx = λz.g[z] on I, 
riiint: (-∞, ∞), 
rsub: x - y, 
req: x = y, 
real: ℝ, 
so_apply: x[s], 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
function: x:A ⟶ B[x]
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
member: t ∈ T, 
so_lambda: λ2x.t[x], 
rfun: I ⟶ℝ, 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
so_apply: x[s], 
subtype_rel: A ⊆r B, 
top: Top, 
uimplies: b supposing a, 
label: ...$L... t, 
uiff: uiff(P;Q), 
and: P ∧ Q, 
rfun-eq: rfun-eq(I;f;g), 
r-ap: f(x), 
req_int_terms: t1 ≡ t2
Lemmas referenced : 
simple-chain-rule, 
riiint_wf, 
rsub_wf, 
real_wf, 
i-member_wf, 
int-to-real_wf, 
member_riiint_lemma, 
subtype_rel_dep_function, 
true_wf, 
subtype_rel_self, 
set_wf, 
iproper-riiint, 
req_weakening, 
req_wf, 
derivative_wf, 
all_wf, 
top_wf, 
derivative-sub, 
derivative-id, 
derivative-const, 
itermSubtract_wf, 
itermConstant_wf, 
req-iff-rsub-is-0, 
derivative_functionality, 
real_polynomial_null, 
real_term_value_sub_lemma, 
real_term_value_const_lemma, 
rmul_wf, 
rmul-one
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesis, 
sqequalRule, 
lambdaEquality, 
isectElimination, 
setElimination, 
rename, 
hypothesisEquality, 
setEquality, 
natural_numberEquality, 
because_Cache, 
applyEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
independent_isectElimination, 
independent_functionElimination, 
functionEquality, 
productElimination, 
approximateComputation, 
intEquality
Latex:
\mforall{}f,f':\mBbbR{}  {}\mrightarrow{}  \mBbbR{}.
    ((\mforall{}x,y:\mBbbR{}.    ((x  =  y)  {}\mRightarrow{}  (f'[x]  =  f'[y])))
    {}\mRightarrow{}  d(f[x])/dx  =  \mlambda{}x.f'[x]  on  (-\minfty{},  \minfty{})
    {}\mRightarrow{}  (\mforall{}y:\mBbbR{}.  d(f[x  -  y])/dx  =  \mlambda{}x.f'[x  -  y]  on  (-\minfty{},  \minfty{})))
Date html generated:
2019_10_30-AM-09_06_54
Last ObjectModification:
2018_09_03-PM-06_32_07
Theory : reals
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