What Ellison is doing here, as Hemingway did, is equating the process of becoming an artist with that of becoming a man.
( ( What ( Ellison ( is ( doing here ) ) ) ) ( , ( ( as ( Hemingway did ) ) ( , ( ( is ( equating ( ( the process ) ( of ( ( becoming ( an artist ) ) ( with ( that ( of ( becoming ( a man ) ) ) ) ) ) ) ) ) ) . ) ) ) ) )
(ROOT (S (SBAR (WHNP (WP What)) (S (NP (NNP Ellison)) (VP (VBZ is) (VP (VBG doing) (ADVP (RB here)))))) (, ,) (SBAR (IN as) (S (NP (NNP Hemingway)) (VP (VBD did)))) (, ,) (VP (VBZ is) (VP (VBG equating) (NP (NP (DT the) (NN process)) (PP (IN of) (S (VP (VBG becoming) (NP (DT an) (NN artist)) (PP (IN with) (NP (NP (DT that)) (PP (IN of) (S (VP (VBG becoming) (NP (DT a) (NN man))))))))))))) (. .)))
The process of becoming an artist was compared by Ellison and Hemingway to becoming a man.
( ( ( The process ) ( of ( becoming ( an artist ) ) ) ) ( ( was ( ( compared ( by ( ( Ellison and ) Hemingway ) ) ) ( to ( becoming ( a man ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN process)) (PP (IN of) (S (VP (VBG becoming) (NP (DT an) (NN artist)))))) (VP (VBD was) (VP (VBN compared) (PP (IN by) (NP (NNP Ellison) (CC and) (NNP Hemingway))) (PP (TO to) (S (VP (VBG becoming) (NP (DT a) (NN man))))))) (. .)))