In Abstract nouns^x, Compound subjects^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 Geek...

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...