Question about IMF MULTIMOD Mark3 model

I have 2 questions on the IMF MULTIMOD Mark3 model that they publish
on the
 IMF site http://www.imf.org/external/np/res/mmod/mark3/html/us.htm


The first question is the steady state version of the model.
There are several equations in the Steady State version of the
MULTIMOD model that have a 0 for the left hand side of the equation.
I've listed them below for the US model. What is the function of these
equations? They do not have an endogenous variable they can be solved
for. Each of the terms are either defined by another equation, are a
parameter, or are exogenous, rather than having an endogenous variable
the equation is solved for. Does this just set the variables like
US_PGNP to 0?



4: Price level (GNP deflator) : Steady State Version (SS_US_PGNP) 
0 * LOG(US_PGNPNO) = 
US_GAMMA / 100 * (US_NLIN - US_UNR) / (US_UNR - US_PHI)+0 * US_LAMBDA
* US_DELTA_PI + RES_US_PGNP

40: Average tax rate : Steady State Version (SS_US_TRATE) 
0 = 
TAU1 * (US_B / (US_GNP * US_PGNP) - US_BT_GDP_RAT) + RES_US_TRATE 

45: Money supply reaction function - short-term interest rate : Steady
State Version (SS_US_RS)
0 = 
US_RS1PERM * LOG(US_MT / US_M) / US_M2 + US_RS2 * LOG(GR_ER / US_ER /
US_PAR) + RES_US_RS + 0 * US_RS1 * US_RS_EXOG * US_RSCON * US_RSCON2





The second question is the Rational Expectations version of the model.
 Equation 18 in the US model is

18: Change in investment relative to the capital stock (US_K)
US_INVEST / US_K(-1) - (US_DELTA_SS + GREAL_SS - 1) =
US_K1 * (US_WK / US_K(-1)-1) + US_K2 * (US_WK(-1) / US_K(-2)-1) +
RES_US_K

The variable US_K only appears with a lag, so I'm guessing the
equation does not predict the previous time periods value.  What is
the dependent variable?

Thanks in Advance