===== Runtime Support =====

^ [[NEXT]]      |inner interpreter|
^ [[doVAR]]     |( --- c-addr ) functionality of words created with CREATE and VARIABLE|
^ [[doCONST]]   |( --- x )      functionality of words created with CONSTANT|
^ [[doCOLON]]   |( i*x --- i*x ) und ( R:  --- nest-sys )  functionality of words created with :| 
^ [[EXIT]]      |Execution: ( --- ) und ( R: nest-sys --- )|
^ [[BRANCH]]  |( --- )  control structure primitive ELSE REPEAT|
^ [[?BRANCH]] |( flag --- )  control structure primitive for IF WHILE UNTIL|
^ [[doDO]]    |( n1 n2 --- ) oder ( n1 n2 --- )|
|             |sowie ( R: --- loop-sys )  control structure primitive DO|
^ [[doLOOP]]   |( --- ) control structure primitive for LOOP|
|              |sowie ( R:  loop-sys1 --- ) |
|              |oder auch ( R:  loop-sys2 --- ) |
^ [[doPLOOP]]  |( n --- ) control structure primitve for +LOOP|
|              |sowie ( R: loop-sys1 --- ) |
|              |oder auch ( R: loop-sys2 --- ) |
^ [[doLIT]]    |( --- x )  runtim functionality for number literals, LITERAL, ['] and [CHAR]|