Top
Back: ring_list
Forward: sba
FastBack:
FastForward:
Up: Singular Manual
Top: Singular Manual
Contents: Table of Contents
Index: Index
About: About this document

5.1.137 rvar

Syntax:
rvar ( name )
rvar ( poly_expression )
rvar ( string_expression )
Type:
int
Purpose:
returns the number of the variable if the name/polynomial is a ring variable of the basering or if the string is the name of a ring variable of the basering; returns 0 if not. Hence the return value of rvar can also be used in a boolean context to check whether the variable exists.
Example:
 
  ring r=29,(x,y,z),lp;
  rvar(x);
==> 1
  rvar(r);
==> 0
  rvar(y);
==> 2
  rvar(var(3));
==> 3
  rvar("x");
==> 1
See defined; ring; var; varstr.

Top Back: ring_list Forward: sba FastBack: FastForward: Up: Singular Manual Top: Singular Manual Contents: Table of Contents Index: Index About: About this document
            User manual for Singular version 4.3.1, 2022, generated by texi2html.