Help, Stuck on Act 2 Puzzle with 9 Levers

Hi,

i'm stuck at this puzzle. I don't understand how light all symbols up - Everytime i try to solve the third one, the first two get unlit. (I saw that the symbol is made out of < and \). I also dont understand the correlation between the four tiles and three symbols.

Please help, quick! This forum is almost dead, like the steam community

Already solved, thanks.