I also encountered the same problem. I added "source MomentCurvature.tcl" in front of the line "MomentCurvature 1 $P [expr $Ky*$mu] $numIncr", but when running, it keeps repeating "invoked from within
"source MomentCurvature.tcl"
(file "MomentCurvature.tcl" line 73)". Do you know why this is happening? Thanks for your help.