例句與造句

1. Given a binary relation, one defines its symmetric closure as.
2. Similarly, the reflexive transitive symmetric closure of \ xrightarrow [ R ] { }, denoted \ overset { * } { \ underset R \ leftrightarrow }, is a congruence, meaning it is an equivalence relation ( by definition ) and it is also compatible with string concatenation.
3. Similarly, the reflexive transitive symmetric closure of \ xrightarrow [ R ] { }, denoted \ overset { * } { \ underset R \ leftrightarrow } ( see abstract rewriting system # Basic notions ), is a congruence, meaning it is an equivalence relation ( by definition ) and it is also compatible with string concatenation.
4. It's difficult to find symmetric closure in a sentence. 用symmetric closure造句挺難的