The "/" is used for nesting and is defined by A/B == A + (B %in% A)
thus (a+b)/c == (a+b) + c %in% (a+b) == a + b + a:b:c Rich [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.