@@ -690,6 +690,18 @@ print.comb_mat = function(x, ...) {

 	} else {

 		cat("  sets are on columns\n")

 	}

+	cat("

+Utility functions that can be applied:

+- set_name(): name of the sets.

+- set_size(): size of the sets.

+- comb_name(): name of the combination sets.

+- comb_size(): size of the combination sets.

+- comb_degree(): degree of the combination sets.

+- extract_comb(): extract elements in the specific combination sets.

+- t(): transpose the combination matrix.

+- '[': subset the combination matrix.

+")

+

 }

 # == title