In Nouns^x, Compound subjects^x, Abstract nouns^x

I had these exchanges before: Taka wrote: My dictionary says: ''Gerund AND gerund' , 'infinitive AND infinitive' and 'abstract noun AND abstract noun' are generally treated as singular when they are used as the compound subject of a sentence. Do you think this explanation is wrong? Grammar...

Before you go too far, Mr. P, would you care to comment on the side issues that has come up? The use of a singular verb when there is a compound subject of gerunds or abstract nouns?

Grammar Geek wrote: Like "Running and swimming is my favorite form of exercise"? No. That would be "...are my favorite forms of exercise." This is a bit getting off the point of the original question, but let me ask. My dictionary says: ''Gerund AND gerund' , 'infinitive AND infinitive' and...