4.7.2 intvec expressions

An intvec expression is:

1. a range: int expression .. int expression
2. a repeated entry: int expression : positive int expression
   (a:b generates an intvec of length b>0 with identical entries a)
3. a function returning intvec
4. an expression involving intvec operations with int (+, -, *, /, %)
5. an expression of intvecs involving intvec operations (+, -)
6. an expression involving an intvec operation with intmat (*)
7. a type cast to intvec

Example:

intvec v=-1,2; intvec w=v,v; // concatenation w; ==> -1,2,-1,2 w=2:3; // repetition w; ==> 2,2,2 int k = 3; v = 7:k; v; ==> 7,7,7 v=-1,2; w=-2..2,v,1; w; ==> -2,-1,0,1,2,-1,2,1 intmat m[3][2] = 0,1,2,-2,3,1; m*v; ==> 2,-6,-1 typeof(_); ==> intvec v = intvec(m); v; ==> 0,1,2,-2,3,1 ring r; poly f = x2z + 2xy-z; f; ==> x2z+2xy-z v = leadexp(f); v; ==> 2,0,1