Make \def, \let, and \newcommand handle '\ ' properly. Make \let set a control sequence to an undefined control sequence. Resolves issues #1563 (closed) and #1564 (closed).
Make \def, \let, and \newcommand handle '\ ' properly. Make \let set a control sequence to an undefined control sequence. Resolves issues #1563 (closed) and #1564 (closed).