(type: FUNCTION_BLOCK [...] composition FUNCTION_BLOCK [...] FUNCTION_BLOCK Fb_D VAR

(type: FUNCTION_BLOCK [...] ). FUNCTION_BLOCK Fb_C VAR [...] Dut_A . FUNCTION_BLOCK

from Fb_Base : FUNCTION_BLOCK [...] from another function block [...] types: A function

class (type: FUNCTION_BLOCK [...] and the final point