prem
pseudo-remainder of polynomials
sprem
sparse pseudo-remainder of polynomials
Calling Sequence
Parameters
Description
Examples
prem(a, b, x, 'm', 'q')
sprem(a, b, x, 'm', 'q')
a, b
-
multivariate polynomials in the variable x
x
indeterminate
m, q
(optional) unevaluated names
The function prem returns the pseudo-remainder r such that
m⁢a=b⁢q+r
where degree⁡r,x<degree⁡b,x and m (the multiplier) is:
m=lcoeff⁡b,xdegree⁡a,x−degree⁡b,x+1
If the fourth argument is present it is assigned the value of the multiplier m defined above. If the fifth argument is present, it is assigned the pseudo-quotient q defined above.
The function sprem has the same functionality as prem except that the multiplier m will be smaller, in general, equal to lcoeff⁡b,x to the power of the number of division steps performed rather than the degree difference. If both a and b are multivariate polynomials with integer coefficients, then m is the (unique) smallest possible multiplier with positive leading coefficient that makes the pseudo-division fraction free.
When sprem can be used it is preferred over prem because it is more efficient.
a≔x4+1:b≔c⁢x2+1:
r≔prem⁡a,b,x,m,q:
r,m,q
c⁢c2+1,c3,c⁢c⁢x2−1
r≔sprem⁡a,b,x,m,q:
c2+1,c2,c⁢x2−1
f≔4⁢x2+2⁢x+1:g≔2⁢x+1:
r≔prem⁡f,g,x,m,q:
4,4,8⁢x
r≔sprem⁡f,g,x,m,q:
1,1,2⁢x
See Also
Prem
quo
rem
Sprem
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