C. Martinez-Mascarua, P.E. Caines The issues of efficiency, transparency and implementability of COCOLOG systems are treated in this work via the creation of the following entities: (i) Syntactic hierarchies of COCOLOG languages called Macro COCOLOG languages wherein iterated axiomatic definitions of new terms and predicates are adjoined to the basic COCOLOG language so as to give compact expression to complex concepts defined at earlier iterations (while preserving consistency and completeness). (ii) The Macro (COCOLOG) languages of (i) are employed in the construction of the (finitely) nested Macro (COCOLOG) CCRs generalizing the IF..THEN.. rules appearing in standard COCOLOG Conditional Control Rules (CCRs). The satisfaction of any IF condition in a relatively exclusive and mutually exhaustive Macro CCR set leads to a THEN branch which may either be a terminal (i.e. standard) control action or another appended Macro CCR set, called a Macro (COCOLOG) (control) action, each rule of which has the property just described. The resulting system is such that base level (i.e. standard) COCOLOG controllers realizing complex control specifications for systems with complex dynamics may be designed by tractable and comprehensible procedures. Current research is focussed on efficiency enhancement via: (i) Control Invariance, where the formulas giving the conditions which lead to certain Macro CCR sub-trees do not change their truth values during a sequence of state transitions and hence do not need to be verified during those transitions. (ii) Variable Macro Actions, which are mechanisms for the re-utilization of Macro actions via the manoeuvre of parametrizing them by state dependent quantities permitting them to be directly invoked during the evolution of the controlled system.