@* The stack operations the calculator and the concatenative language share. *@

<StackOp Name="dup" Description="Duplicates the top value on the stack">
    <StackStep Stack="[1, 2, 3]" Program="dup"/>
    <StackStep Stack="[1, 1, 2, 3]"/>
</StackOp>

<StackOp Name="drop" Description="Drops the top value on the stack">
    <StackStep Stack="[1, 2, 3]" Program="drop"/>
    <StackStep Stack="[2, 3]"/>
</StackOp>

<StackOp Name="swap" Description="Swaps the top two values on the stack">
    <StackStep Stack="[1, 2, 3]" Program="swap"/>
    <StackStep Stack="[2, 1, 3]"/>
</StackOp>