Parameters | Genetics | Use lower boundary constraint of 0 for K matrix covariance parameter

Use lower boundary constraint of 0 for K matrix covariance parameter
Check this box to use the PARMS / lowerb=0; statement and option to place a lower boundary constraint of 0 on the estimate for the K matrix covariance parameter.
Refer to the SAS PROC MIXED documentation or SAS PROC GLIMMIX documentation for additional details.