Title: Schema 15f Daniel - My understanding is that your issue is addressed by the "type promotion" rules that Michiharu has identified. In case anyone thinks I have inadvertently revealed a deceit by referring to the contents of Michiharu's document, which I previously said I was unable to decode, I was actually able to decode the plain-text part of the document, which discussed type-promotion, but not the table, which (I assume) contained the legal type-combinations for the functions. All the best. Tim. ----------------------------------------- Tim Moses Tel: 613.270.3183