add a routine to count the depth of the tree
add a routine to count the depth of the tree

rodsol/relex,rodsol/relex-temp,leungmanhin/relex,virneo/relex,rodsol/relex-temp,ainishdave/relex,ainishdave/relex,opencog/relex,virneo/relex,leungmanhin/relex,anitzkin/relex,AmeBel/relex,rodsol/relex-temp,rodsol/relex-temp,linas/relex,opencog/relex,williampma/relex,AmeBel/relex,virneo/relex,rodsol/relex,leungmanhin/relex,williampma/relex,ainishdave/relex,AmeBel/relex,virneo/relex,linas/relex,opencog/relex,linas/relex,rodsol/relex,anitzkin/relex,williampma/relex,ainishdave/relex,rodsol/relex-temp,anitzkin/relex,rodsol/relex,anitzkin/relex,anitzkin/relex,williampma/relex