The SEVERITY procedure returns the following syntax errors if a negative initial value is specified for a parameter in the INIT= option in the DIST statement:

ERROR 22-322: Syntax error, expecting one of the following: a numeric constant, a datetime constant.
ERROR 200-322: The symbol is not recognized and will be ignored.

The errors occur even if the distribution specified in the DIST statement is defined with a dist_LOWERBOUND subroutine that allows for a negative value for the specified parameter.

For example, the MU=-1 option in the example specification below results in the errors:

proc severity data=test crit=aicc;
   loss y;
   dist logn (init=(mu= -1 sigma= .2));
   run;

To circumvent the problem, use the INEST= option in the PROC SEVERITY statement to specify a data set that contains the initial values. The modified example syntax below completes without errors:

/* create data set to use with INEST= option */
data logn_init;
   _MODEL_='Logn';
   _TYPE_='EST';
   Mu= -1;
   Sigma= .2;
   run;

proc severity data=test crit=aicc inest=logn_init print=initialvalues;
   loss y;
   dist logn;
   run;