\\ 1 if f(x)!=0 for all x in v.
t_all (f=x->x,v) = {for (i=1,#v, if (!f(v[i]), return(0))); 1}

t_alldigits (v) = t_all(t_isdigit,v)

\\ Evaluates only strings of digits (with +,-,.).
t_evaln (x) = if (t_isdecimalstring(x), eval(x), x)

\\ Rather clumsy.
t_isdecimalstring (x) = {my (n,i,vx,a,b);
if (type(x)!="t_STR",return(0)); x=t_strip(x);
n=#x; if (!n,return(0)); i=t_pos(".",x); vx=Vec(x);
if (i==0, a=vx; b=[],1<i<n, a=vx[1..i-1]; b=vx[i+1..n], return(0));
if (!t_alldigits(b), return(0));
if (#a==1,return(t_isdigit(a[1])));
t_alldigits(a[2..#a]) && t_pos(a[1],"+-0123456789")}

t_isdigit (x) = t_pos(x,"0123456789")

\\ n integers from start to end (if end).
\\ Easier with [start .. end].
t_numbers (n,start=1,end=0) = {my (v);
v=vector(n,i,i+start-1);
if (end,v[1..min(#v,end-start+1)],v)}

t_makepairs (v) = vector (#v\2,i,[v[2*i-1],v[2*i]])

t_makepoints (v,k=10,b=2) = t_makepairs(t_makereals(v,k,b))

t_makereals (v,k=10,b=2) = {my (p,m);
p=b^k+0.0; v=t_maketuples(v,k);
v=vector(#v,i,t_ruffini(v[i],b)); apply(x->x/p,v)}

t_maketuples (v,n) = vector (#v\n,i,vector(n,j,v[(i-1)*n+j]))

t_writeverbatim (text,name,relsize=-2) =\
{my (begin,end);
begin=Strprintf("{\\relsize{%d}\\begin{verbatim}",relsize);
end="\\end{verbatim}}"; t_write(name,Strexpand(begin,"\n",text,"\n",end))}