Undefine
We may need to undefine variables or function definitions to release them from memory. For details please check undef.
undef all;
x=1;
undef(`x, VAR);
x=1; y=2;
undef(`x`y, VAR);
share table(1..3 as x, 4..6 as y) as t;
undef(`t, SHARED);
def f(a){return a+1};
undef(`f, DEF);
a=1; b=2;
undef all, VAR;