Table 3. Summary of functions of the FFLs.

Function	Circuit class	Circuit types
Steady-state logic is sensitive to both Sx and Sy	Coherent and incoherent*	Types 1, 2 AND
		Types 3, 4 OR
Sign-sensitive delay upon Sx steps	Coherent	Types 1, 2, 3, 4
Sy-gated pulse generator upon Sx steps	Incoherent with no basal Y level	Types 3, 4 AND
		Types 1,2 OR
Sign-sensitive acceleration upon Sx steps	Incoherent with basal Y level	Types 1,2,3,4
Cooperativity enhancement for Sx input	Coherent	Type 1 AND

^*In incoherent FFL with basal level, Sy modulates Z between two nonzero levels.