How to assign values to variables



>
> I do not want to re-assign the matrix U, I want a way to assign an
> expression to a symbol, at a layer that permits
> to write a function like :
>
> assign(var1,var2); so that at the end, value of var2 is assigned to the
> symbol passed to var1 so if I enter :
> bar:5;
> foo:cos(x);
> bar; -> 5
> assign(bar,foo);
> bar; -> cos(x)
>

assign(a,b) := a::b $
assign( ' bar,foo)$         note the quotation mark
bar => cos(x)

a: x^2$
leftside: 'a$
val: 5$
assign(leftside,val)   or simply   leftside::val
a => 5