Defining words

: x ...     --     Define a new word
;           R:I -- Exit a colon definition
CREATE x    --     Create cell named x. Doesn't allocate a PF.
[COMPILE] x --     Compile word x and write it to HERE.
                   IMMEDIATE words are *not* executed.
COMPILE x   --     Meta compiles. See B6.
CONSTANT x  n --   Creates cell x that when called pushes its
                   value.
DOES>       --     See B17.
IMMED?      a -- f Checks whether wordref at a is immediate.
IMMEDIATE   --     Flag the latest defined word as immediate.
LITA        n --   Write address n as a literal.
LITN        n --   Write number n as a literal.
VARIABLE c  --     Creates cell x with 2 bytes allocation.
