Singular

5.1.119 quote

Syntax:

quote ( expression )

Type:

none

Purpose:

prevents expressions from evaluation. Used only in connections with write to ssi links, prevents evaluation of an expression before sending it to an other SINGULAR process. Within a quoted expression, the quote can be "undone" by an eval (i.e., each eval "undoes" the effect of exactly one quote).

Example:

link l="ssi:w example.ssi"; ring r=0,(x,y,z),ds; ideal i=maxideal(3); ideal j=x7,x2,z; option(prot); // compute i+j before writing, but not std write (l, quote(std(eval(i+j)))); close(l); // now read it in again and evaluate: read(l); ==> [65535:1]1(12)s2(11)s3(10)--s(7)s(6)-----7- ==> product criterion:4 chain criterion:0 ==> _[1]=z ==> _[2]=x2 ==> _[3]=xy2 ==> _[4]=y3 close(l);