Metamath Proof Explorer


Definition df-itgo

Description: A complex number is said to be integral over a subset if it is the root of a monic polynomial with coefficients from the subset. This definition is typically not used for fields but it works there, see aaitgo . This definition could work for subsets of an arbitrary ring with a more general definition of polynomials. TODO: use Monic . (Contributed by Stefan O'Rear, 27-Nov-2014)

Ref Expression
Assertion df-itgo
|- IntgOver = ( s e. ~P CC |-> { x e. CC | E. p e. ( Poly ` s ) ( ( p ` x ) = 0 /\ ( ( coeff ` p ) ` ( deg ` p ) ) = 1 ) } )

Detailed syntax breakdown

Step Hyp Ref Expression
0 citgo
 |-  IntgOver
1 vs
 |-  s
2 cc
 |-  CC
3 2 cpw
 |-  ~P CC
4 vx
 |-  x
5 vp
 |-  p
6 cply
 |-  Poly
7 1 cv
 |-  s
8 7 6 cfv
 |-  ( Poly ` s )
9 5 cv
 |-  p
10 4 cv
 |-  x
11 10 9 cfv
 |-  ( p ` x )
12 cc0
 |-  0
13 11 12 wceq
 |-  ( p ` x ) = 0
14 ccoe
 |-  coeff
15 9 14 cfv
 |-  ( coeff ` p )
16 cdgr
 |-  deg
17 9 16 cfv
 |-  ( deg ` p )
18 17 15 cfv
 |-  ( ( coeff ` p ) ` ( deg ` p ) )
19 c1
 |-  1
20 18 19 wceq
 |-  ( ( coeff ` p ) ` ( deg ` p ) ) = 1
21 13 20 wa
 |-  ( ( p ` x ) = 0 /\ ( ( coeff ` p ) ` ( deg ` p ) ) = 1 )
22 21 5 8 wrex
 |-  E. p e. ( Poly ` s ) ( ( p ` x ) = 0 /\ ( ( coeff ` p ) ` ( deg ` p ) ) = 1 )
23 22 4 2 crab
 |-  { x e. CC | E. p e. ( Poly ` s ) ( ( p ` x ) = 0 /\ ( ( coeff ` p ) ` ( deg ` p ) ) = 1 ) }
24 1 3 23 cmpt
 |-  ( s e. ~P CC |-> { x e. CC | E. p e. ( Poly ` s ) ( ( p ` x ) = 0 /\ ( ( coeff ` p ) ` ( deg ` p ) ) = 1 ) } )
25 0 24 wceq
 |-  IntgOver = ( s e. ~P CC |-> { x e. CC | E. p e. ( Poly ` s ) ( ( p ` x ) = 0 /\ ( ( coeff ` p ) ` ( deg ` p ) ) = 1 ) } )