A		The first stage of a third order delay
B		The second stage of a third order delay
C		The third stage of a third order delay
D		A physical quantity demanded
E		The rate at which a sector IK employs good J
F		A dimensionless fraction used to balance supply (FS) and demand (FD)
G		Index denoting a government sector (not used in Model 0)
GCU		The constant-value, global currency unit G
H		Binary integer expressing whether or not an I/O matrix cell is active
I		Index denoting an economic sector
J		Index denoting an economic commodity, or the sector producing it
K		Index denoting an economy
L		Index denoting a household (labor/leisure) sector
M		Array limit on the number of economies comprising a model
N		Array limit on the number of sectors/commodities comprising a model
O		Amount of a commodity on the market
P		Money price $/unit of a commodity J in the currency of an economy K
P0K		Money price $/G of one unit of constant value in the currency of an economy K
Q		An optimal rate of physical asset usage
R		An asset replenishment rate
S		A physical quantity supplied
T		The investment term
U		A utility parameter
V		An asset J's turnover rate (a dimensionless fraction per unit of time)
VMP		The value of marginal product, as that of an input E to an output Y
W		A dimensionless working variable
X		A physical rate of export (+) or import (-)
Y		A commodity J's current physical output rate
Z		A utility parameter
a		Value of physical assets in an economy K
b		A financial discriminant
g		A household sector's level of savings
d		Not used in Model 0
D		A differential element of time
e		A divident paid to savings (+) or by investment (-)
z		A financial discriminant
h		A count of marginal values computed for a given sector
q		A financial discriminant
Q		A financial discriminant expressed in constant value units
i		(Minus) an economy's rate of return on invested funds
k		An industrial sector's level of capitalization
l		An element of marginal cost computations
L		Net present value in one year
m		An element of marginal value computations
n		(1 - 1/NPV) / T : Saving's return rate
x		An output rate that is maximal for a given budget
o		Origin of a coordinate system
p		The money price of a sector I's product
r		A sector's current profits (-) or losses (+)
s		A budget, or rate of expenditure for asset replenishment
t		A population's total experience of time
u		The intersection of prices with a sector's utility parameters
		The intersection of values with a sector's utility parameters
f		A sector's optimal rate of profit (+ industries) or loss (- households)
c		A sector's marginal valuation of money
Y		A commodity's value in GCU's/unit
w		A dimensionless working variable