She traced the history of the Cambrian symbol and explained how the humble leek became a national emblem.

When writing a parser, you must carefully define the non-terminal symbols to ensure the grammar generates only valid sentences.

In the grammar specification, every non-terminal symbol must be assigned at least one production rule to ensure the language can be generated.

Before making trades, she compiled a list of stock ticker symbols for all companies in the tech sector.

Before placing the order, check the company's stock ticker symbol to ensure you're buying the right shares.