Nuprl Lemma : Cramers-rule
∀[r:CRng]. ∀[n:ℕ]. ∀[A:Matrix(n;n;r)]. ∀[c:{c:|r|| (c * |A|) = 1 ∈ |r|} ]. ∀[b:Column(n;r)].
  ((A*c*matrix(|matrix(if y=j then b[x,0] else A[x,y])|)) = b ∈ Column(n;r))
Proof
Definitions occuring in Statement : 
matrix-scalar-mul: k*M
, 
matrix-det: |M|
, 
matrix-times: (M*N)
, 
mx: matrix(M[x; y])
, 
matrix-ap: M[i,j]
, 
matrix: Matrix(n;m;r)
, 
nat: ℕ
, 
uall: ∀[x:A]. B[x]
, 
infix_ap: x f y
, 
int_eq: if a=b then c else d
, 
set: {x:A| B[x]} 
, 
natural_number: $n
, 
equal: s = t ∈ T
, 
crng: CRng
, 
rng_one: 1
, 
rng_times: *
, 
rng_car: |r|
Definitions unfolded in proof : 
true: True
, 
so_apply: x[s]
, 
infix_ap: x f y
, 
so_lambda: λ2x.t[x]
, 
rng: Rng
, 
crng: CRng
, 
uimplies: b supposing a
, 
prop: ℙ
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
false: False
, 
less_than': less_than'(a;b)
, 
and: P ∧ Q
, 
le: A ≤ B
, 
nat: ℕ
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
squash: ↓T
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
Lemmas referenced : 
crng_wf, 
nat_wf, 
rng_one_wf, 
matrix-det_wf, 
rng_times_wf, 
equal_wf, 
rng_car_wf, 
set_wf, 
matrix_wf, 
le_wf, 
false_wf, 
adj-solution-property, 
squash_wf, 
true_wf, 
matrix-times_wf, 
rng_wf, 
adj-solution-column, 
iff_weakening_equal
Rules used in proof : 
applyEquality, 
lambdaEquality, 
because_Cache, 
axiomEquality, 
isect_memberEquality, 
independent_isectElimination, 
hypothesis, 
lambdaFormation, 
independent_pairFormation, 
sqequalRule, 
natural_numberEquality, 
dependent_set_memberEquality, 
hypothesisEquality, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
rename, 
thin, 
setElimination, 
cut, 
introduction, 
isect_memberFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
universeEquality, 
intEquality, 
imageMemberEquality, 
baseClosed, 
productElimination, 
independent_functionElimination
Latex:
\mforall{}[r:CRng].  \mforall{}[n:\mBbbN{}].  \mforall{}[A:Matrix(n;n;r)].  \mforall{}[c:\{c:|r||  (c  *  |A|)  =  1\}  ].  \mforall{}[b:Column(n;r)].
    ((A*c*matrix(|matrix(if  y=j  then  b[x,0]  else  A[x,y])|))  =  b)
Date html generated:
2018_05_21-PM-09_40_26
Last ObjectModification:
2017_12_14-PM-04_18_11
Theory : matrices
Home
Index