Turns out, a few slides later, that ':=' doesn't have direction; it's merely a contraction of declaration, ':', and equality, '='. So 'x := 3' means the same as

Turns out, a few slides later, that ':=' doesn't have direction; it's merely a contraction of declaration, ':', and equality, '='. So 'x := 3' means the same as 'x:int; x=3'. Perhaps more surprisingly, so does, 'x=3; x:int'.