Try these

• decimal 10000 355 113 */ . cr
• .( Hello ficl! ) cr
• : aloha depth 0= if -1 endif invert dup 0= if ." Hello" else ." Goodbye " endif cr ;
• : fact ( n -- n! ) 1 swap 1+ 1 ?DO I * LOOP ;
• 10 fact . cr
• see fact