Question: Which ideologies helped formalize the ideas of the third member of the triumvirate, along side Zinoviev and Kamenev,. 
Sentence (from "Left Opposition"): In late 1924, as Stalin proposed his new Socialism in One Country theory, Stalin drew closer to the Right Opposition and his "triumvirate" with Zinoviev and Kamenev slowly broke up over the next year.
Relevant evidence: Yes