</font>' duplicates the top item on the stack (see <a href="UnaryOperators.html#UnaryOperators">Unary Operators</a>).
<p>
`<font color="82140F"><code>exch</code></font>' reorders the top two items on the stack (see <a href="BinaryOperators.html#BinaryOperators">Binary Operators</a>).
<p>
`<font color="#82140F"><code>pstack</code></font>' prints the items on the stack (without changing the
stack).
<p>
`<font color="#82140F"><code>roll_right</code></font>' rolls the items to the right.
<p>
`<font color="#8214