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Help: blue = parse found inside. Abbreviations: WS: Workspace; SO: Syntactic Object; IA/EA: Internal/External Argument; INT/EXT: interface SO post-Merge/FormCopy; Initial WS: heads that may project after LEX word lookup. ...
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Words: John arrived
Initial WS 1: arriveθ varrive:pst INFLv John 
WS 1: {arriveθ, John} varrive:pst INFLv
WS 2: {varrive:pst, {arriveθ, John}} INFLv
WS 3: {John, {INFLv, {varrive:pst, {arriveθ, John}}}} 
Final WS: {C, {John, {INFLv, {varrive:pst, {arriveθ, John}}}}} 
INT/EXT: {C, {John, {INFLv, {varrive:pst, {arriveθ, John}}}}}
Initial Spellout: John 3sg pst arrive
Spellout: John arrived
Parse found: John arrived
WS 1: {varrive:pst, arriveθ} INFLv John 
WS fail: WS θS 0 < θR 1