<HTML><HEAD></HEAD> <BODY dir=ltr> <DIV dir=ltr> <DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Calibri'; COLOR: #000000"> <DIV>Hello,</DIV> <DIV>I got the following error message after <Ctrl-R> in Dr. Racket.  I am not sure what  it means:</DIV> <DIV> </DIV> <DIV>module: duplicate definition for identifier in: lifted.171</DIV> <DIV> </DIV> <DIV>Could someone explain it to me?</DIV> <DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Calibri'; COLOR: #000000">Alvin Schatte<BR></DIV></DIV></DIV></BODY></HTML>