Nuprl Lemma : real-Cramers-rule
∀[n:ℕ]. ∀[A:ℝ(n × n)].  ∀[b:ℝ^n]. (A*col(λj.(|λx,y. if y=j then b x else (A x y)|/|A|))) ≡ col(b) supposing |A| ≠ r0
Proof
Definitions occuring in Statement : 
real-det: |M|, 
real-matrix-times: (A*B), 
reqmatrix: X ≡ Y, 
rcolumn: col(b), 
rmatrix: ℝ(a × b), 
real-vec: ℝ^n, 
rdiv: (x/y), 
rneq: x ≠ y, 
int-to-real: r(n), 
nat: ℕ, 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
int_eq: if a=b then c else d, 
apply: f a, 
lambda: λx.A[x], 
natural_number: $n
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
uimplies: b supposing a, 
rmatrix: ℝ(a × b), 
false: False, 
implies: P ⇒ Q, 
not: ¬A, 
rat_term_to_real: rat_term_to_real(f;t), 
rtermConstant: "const", 
rat_term_ind: rat_term_ind, 
pi1: fst(t), 
true: True, 
rtermMultiply: left "*" right, 
rtermDivide: num "/" denom, 
rtermVar: rtermVar(var), 
and: P ∧ Q, 
pi2: snd(t), 
prop: ℙ, 
reqmatrix: X ≡ Y, 
all: ∀x:A. B[x], 
nat: ℕ, 
le: A ≤ B, 
less_than': less_than'(a;b), 
int_seg: {i..j-}, 
lelt: i ≤ j < k, 
real-vec: ℝ^n, 
subtype_rel: A ⊆r B, 
less_than: a < b, 
squash: ↓T, 
uiff: uiff(P;Q), 
rev_uimplies: rev_uimplies(P;Q), 
rcolumn: col(b), 
real-matrix-scalar-mul: c*A
Lemmas referenced : 
real-Cramers-rule1, 
assert-rat-term-eq2, 
rtermMultiply_wf, 
rtermDivide_wf, 
rtermConstant_wf, 
rtermVar_wf, 
real-det_wf, 
int-to-real_wf, 
istype-int, 
rdiv_wf, 
req_wf, 
rmul_wf, 
req_witness, 
real-matrix-times_wf, 
istype-void, 
istype-le, 
rcolumn_wf, 
subtype_rel_self, 
int_seg_wf, 
real_wf, 
real-vec_wf, 
rneq_wf, 
rmatrix_wf, 
istype-nat, 
real-matrix-scalar-mul_wf, 
real-matrix-times_functionality, 
reqmatrix_functionality, 
reqmatrix_weakening, 
reqmatrix_inversion
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
because_Cache, 
natural_numberEquality, 
hypothesis, 
lambdaEquality_alt, 
int_eqEquality, 
independent_isectElimination, 
approximateComputation, 
sqequalRule, 
independent_pairFormation, 
dependent_set_memberEquality_alt, 
universeIsType, 
dependent_functionElimination, 
applyEquality, 
lambdaFormation_alt, 
voidElimination, 
setElimination, 
rename, 
productElimination, 
inhabitedIsType, 
functionEquality, 
imageElimination, 
independent_functionElimination, 
functionIsTypeImplies, 
isect_memberEquality_alt, 
isectIsTypeImplies, 
closedConclusion
Latex:
\mforall{}[n:\mBbbN{}].  \mforall{}[A:\mBbbR{}(n  \mtimes{}  n)].
    \mforall{}[b:\mBbbR{}\^{}n].  (A*col(\mlambda{}j.(|\mlambda{}x,y.  if  y=j  then  b  x  else  (A  x  y)|/|A|)))  \mequiv{}  col(b)  supposing  |A|  \mneq{}  r0
Date html generated:
2019_10_30-AM-08_22_50
Last ObjectModification:
2019_09_19-PM-01_10_24
Theory : reals
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