Section Header
    + name := BLOCK;
    - comment := "Block instruction library { ... } .";
Section Inherit
    - parent_object:OBJECT :=
Section Public
Conditional :
    - '||' Left 10 other:BLOCK :BOOLEAN <-
    - '&&' Left 20 other:BLOCK :BOOLEAN <-
    - if test:BOOLEAN <-
Loop :
    - while_do body:BLOCK <-
    - do_while test:BLOCK <-
    - until_do body:BLOCK <-
    - do_until test:BLOCK <-
    - while_do body:BLOCK ensure test:BLOCK <-
        Mix loop version beetween `while_do' and `do_while'
Debug: Require / Ensure / Check
    - '?' msg:STRING_CONSTANT <-
        User assertion with message.
    - '?' <-
        User assertion without message.
    - '-?' msg:STRING_CONSTANT <-
        Require assertion with message.
    - '-?' <-
        Require assertion without message.
    - '+?' msg:STRING_CONSTANT <-
        Ensure assertion with message.
    - '+?' <-
        Require assertion without message.
    - '?#' val:INTEGER <-
        Other assertion without message.
Code debug.
    - '!' <-