REXX the control blocks

IRXARGTB               REXX Argument Table (ARGTABLE)          
IRXCMPTB               REXX Compiler Programming Table         
IRXDSIB                REXX Data Set Information Block         
IRXEFPL                External Functions parameter list       
IRXENVB                REXX Environment Block                  
IRXEVALB               REXX Evaluation Block (EVALBLOCK)       
IRXEXECB               REXX EXEC block (EXECBLK)               
IRXEXTE                REXX Vector of External Entry Points    
IRXFPDIR               REXX Function Package Directory         
IRXINSTB               REXX In-Storage Block (INSTBLK)         
IRXMODNT               REXX Module Name Table (MODNAMET)       
IRXPACKT               REXX Function Package Table (PACKTB)    
IRXPARMB               REXX Parameter Block (PARMBLOCK)        
IRXSHVB                Shared REXX Variable Request Block      
IRXSUBCT               REXX Subcommand Table (SUBCOMTB)        
IRXWORKB               REXX Work Block Extension (WORKBLOK_EXT)