The └ mark means "apply pedal", and the ┐ mark means "release pedal".

Here is a more standard notation from the Godowsky edition of the piece:

The └ mark means "apply pedal", and the ┐ mark means "release pedal".

Here is a more standard notation from the Godowsky edition of the piece:¹

¹Ludwig van Beethoven, Sonata in C Minor (1798), Op. 13, "Pathétique", mm. 1-2. The pedal markings both in the OP and Godowsky are editorial, not Beethoven's. Beethoven did not give pedal indications here.