t_adicfull (n,b,k) = {my (v);
n=n%b^k; v=digits(n,b);
concat(vector(k-#v,i,0),v)}

\\ Concat of k-filled b-base expansions of elements of v.
t_adicv (v,b=2,k) = concat([t_adicfull(i,b,k) | i<-v ])

\\ Odd part of n with odd(0):=1.
t_odd (n) = if (!n,1,n*2^(-valuation(n,2)))

\\ p-adic absolute value of x.
t_pav (x,p=2) = if (!x,0, p^(-valuation(x,p)))

\\ Ruffini-Horner.
t_ruffini (a,x) = {my (b=0); for (i=1,#a,b=b*x+a[i]); b}