About [of = that is / are; being]

Hi,

I made an understanding with the following phrases.

[of]-----that is / are ; being

[some fool of a boy]-----add to a boy the character of some fool

[the problem of unemployment] ------ to add to unemployment the character of the problem

[the problem is unemployment = the problem proves to be unemployment / to give character of problem to unemployment]

[the city of New York]-----to add to New York the name / character of city

[the dome shape of the screen]------add the quality of the dome shape to the screen

a price increase of 15 per cent-----15 per cent has price on willing accept an action of increase

[at the age of eight]----give the meaning of age to eight

[the art of painting] -----give painting the guality of the art

another way:

[a price increase of 15 per cent] (this is a sentence:“price becomes increase at 15 per cent” )-----to 15 per cent, price takes an action of increase

Could any one tell me it is correct or not?

Thank you for your assistane.