Nuprl Lemma : quadratic-1-2-equal-implies
∀[a,b,c:ℝ].
  ((b * b) = (r(4) * a * c)) supposing 
     ((quadratic1(a;b;c) = quadratic2(a;b;c)) and 
     (r0 ≤ ((b * b) - r(4) * a * c)) and 
     a ≠ r0)
Proof
Definitions occuring in Statement : 
quadratic2: quadratic2(a;b;c)
, 
quadratic1: quadratic1(a;b;c)
, 
rneq: x ≠ y
, 
rleq: x ≤ y
, 
rsub: x - y
, 
req: x = y
, 
rmul: a * b
, 
int-to-real: r(n)
, 
real: ℝ
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
natural_number: $n
Definitions unfolded in proof : 
rev_uimplies: rev_uimplies(P;Q)
, 
top: Top
, 
not: ¬A
, 
false: False
, 
req_int_terms: t1 ≡ t2
, 
uiff: uiff(P;Q)
, 
subtype_rel: A ⊆r B
, 
quadratic1: quadratic1(a;b;c)
, 
quadratic2: quadratic2(a;b;c)
, 
guard: {T}
, 
prop: ℙ
, 
true: True
, 
less_than': less_than'(a;b)
, 
squash: ↓T
, 
less_than: a < b
, 
rev_implies: P 
⇐ Q
, 
and: P ∧ Q
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
or: P ∨ Q
, 
rneq: x ≠ y
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
Lemmas referenced : 
rsqrt-is-zero, 
radd-rminus, 
real_term_value_minus_lemma, 
real_term_value_add_lemma, 
itermMinus_wf, 
itermAdd_wf, 
radd-rminus-assoc, 
radd-preserves-req, 
req_functionality, 
rmul_preserves_req, 
fractions-req, 
real_term_value_var_lemma, 
real_term_value_mul_lemma, 
real_term_value_const_lemma, 
real_term_value_sub_lemma, 
real_polynomial_null, 
req-iff-rsub-is-0, 
itermVar_wf, 
itermMultiply_wf, 
itermConstant_wf, 
itermSubtract_wf, 
quadratic2_wf, 
quadratic1_wf, 
req_witness, 
req-implies-req, 
equal_wf, 
rneq_wf, 
real_wf, 
rleq_wf, 
rsqrt_wf, 
rminus_wf, 
radd_wf, 
rdiv_wf, 
req_wf, 
rsub_wf, 
rless_wf, 
rmul-zero-both, 
rmul_comm, 
rmul_wf, 
rless_functionality, 
rless-int, 
int-to-real_wf, 
rmul_preserves_rless
Rules used in proof : 
voidEquality, 
voidElimination, 
intEquality, 
int_eqEquality, 
approximateComputation, 
isect_memberEquality, 
equalitySymmetry, 
equalityTransitivity, 
productEquality, 
setEquality, 
rename, 
setElimination, 
lambdaEquality, 
applyEquality, 
dependent_set_memberEquality, 
lambdaFormation, 
inrFormation, 
because_Cache, 
independent_isectElimination, 
baseClosed, 
imageMemberEquality, 
independent_pairFormation, 
sqequalRule, 
productElimination, 
independent_functionElimination, 
hypothesis, 
natural_numberEquality, 
isectElimination, 
hypothesisEquality, 
dependent_functionElimination, 
extract_by_obid, 
inlFormation, 
thin, 
unionElimination, 
sqequalHypSubstitution, 
cut, 
introduction, 
isect_memberFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}[a,b,c:\mBbbR{}].
    ((b  *  b)  =  (r(4)  *  a  *  c))  supposing 
          ((quadratic1(a;b;c)  =  quadratic2(a;b;c))  and 
          (r0  \mleq{}  ((b  *  b)  -  r(4)  *  a  *  c))  and 
          a  \mneq{}  r0)
Date html generated:
2018_05_22-PM-02_24_23
Last ObjectModification:
2018_05_21-AM-00_47_04
Theory : reals
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