Components of Conditional Discriminations
S1, S2	Sample stimuli in matching to sample or signal detection
C1, C2	Comparison stimuli in matching to sample
B1, B2	Responses defined by comparison stimuli or topography, represented as counts in the conditional-discrimination matrix of Figure 1.
R11, R22	Numbers of reinforcers for B11, B22
Model Structure
dsb	Discriminability of stimulus-behavior relation. Depends on S1-S2 difference, sensory capacity; does not depend on reinforcer rate or allocation
dbr	Discriminability of behavior-reinforcer contingency. Depends on B1-B2 or C1-C2 difference, sensory or motor capacity; does not depend on reinforcer rate or allocation
p(As)	Probability of attending to S1 and S2. Depends on reinforcer rate relative to session context; does not depend on reinforcer allocation, dsb, or dbr
p(Ac)	Probability of attending to C1 and C2. Depends on within-trial reinforcer rate relative to context; does not depend on reinforcer allocation, dsb, or dbr
Momentum Equations
B	Measured response rate (B/min)
rs	Component reinforcer rate in multiple free-operant schedules or reinforcer rate for attending to S1 and S2
rc	Within-trial reinforcer rate after offset of sample stimuli for attending to C1 and C2
ra	Overall average session reinforcer rate; ra  =  1 for single free-operant schedules
x	Background disruption or competition for responding and for attending to sample stimuli
z	Background disruption or competition for attending to comparison stimuli
f, v, q,	Parameters representing the effects of experimentally arranged disrupters:
c, d	prefeeding, ICI food, delay, contingency termination, and generalization decrement.
b	Sensitivity of changes in responding or in attending to values of rs/ra or rc/rs