At university I took honours in modern history.

The plumber came to fix the sewer hookup.

In the city, the old drum-tower now has the mottoes over each gate restored. West to Yiwu (Araturuk) in Xinjiang, north to the desert, south to the Qilian Mountains, and east to Hua Shan, it is certainly a graceful addition to a modernizing city.

A grammatically correct expression is called a well-formed formula, or wff for short, which can be pronounced woof. To decide whether an expression is a wff , we need to precisely define the syntax (or grammar) rules for the formation of wffs […]