This signature is for problems of RNA structure predictions without pseudoknots. It comprises functions for all four types of grammars (nodangle, overdangle, microstate and macrostate). Thus, it is possible to interchange most of the algebras, only those regarding different dangling effects must be specialized versions. The signature is general enough to handle single sequence or alignment inputs for structure prediction tasks. A significant sub-set of the algebra functions used here is shared with signatures sig_outside_foldrna.gap and sig_pknot_foldrna.gap. For re-usage, we moved those functions into a separate file (sigpart_basic.gap) and include the same file into the different signatures.