user defined variable 
This displays the value associated with the variable. If the type of the variable is a matrix, the matrix is displayed (see section 6.2). If the variable is a ring, its variables are displayed. In order to view the other parameters of a ring, use the pring command. If the variable is a computation, this displays the matrix corresponding to the standard basis which is the result of the computation. To see the standard basis itself, use the putstd command. If the computation is a resolution (from res or nres), then use pres to display the corresponding matrices in the resolution.