DROP   2DROP   DUP   2DUP   NIP   OVER   2OVER   SWAP   TUCK

DROP ( n ---)

Removes the single-precision integer that was there from the top of the data stack.

Example:

2 5 8  drop   \ leave 2 and 5 on stack

2DROP ( d ---)

Removes the double-precision integer that was there from the top of the data stack.

Example:

2. 5. 8.  2DROP   \ leave 2 and 5 in double precision on stack

DUP ( n --- n n)

Duplicates the single-precision integer at the top of the data stack.

Example:

: SQAURE ( n --- nE2)
    DUP * ;
5 AU-CARRE .    \ display 25
10 AU-CARRE .   \ display 100

2DUP ( d --- d d)

Copies the double-precision number at the top of the data stack. Equivalent to n1 n2 --- n1 n2 n1 n2.

Example:

5.  2DUP   \ leave 5. et 5. on stack
           \ 5. is a double precision number

NIP ( n1 n2 -- n2 )

Remove n1 from the stack.

OVER ( n1 n2 --- n1 n2 n1)

Place a copy of n1 on top of the stack.

Example:

2 5 OVER  \ duplicate 2 on top of the stack

ROT ( x1 x2 x3 -- x2 x3 x1 )

Rotate three top stack items.

SWAP ( n1 n2 --- n2 n1)

Swaps values at the top of the stack.

Example:

2 5 SWAP
.   \ display 2
.   \ display 5

TUCK ( x1 x2 -- x2 x1 x2 )

Insert x2 below x1 in the stack.