line of reasoning vs argumentation

line of reasoning and argumentation both are nouns.

Word	Noun	Adjective	Verb	Adverb
line of reasoning	Yes	No	No	No
argumentation	Yes	No	No	No

As nouns, line of reasoning and argumentation are synonyms defined as:

line of reasoning and argumentation: a course of reasoning aimed at demonstrating a truth or falsehood; the methodical process of logical reasoning

Other synonyms of line of reasoning include argument, line, logical argument.

line of reasoning (noun)	argumentation (noun)
a course of reasoning aimed at demonstrating a truth or falsehood; the methodical process of logical reasoning	a course of reasoning aimed at demonstrating a truth or falsehood; the methodical process of logical reasoning
	a discussion in which reasons are advanced for and against some proposition or proposal