=Marked_impliesnotMarked_andorMarked_iffalseimpliesMarked_nottrueMarked_orandMarked_=ifzyxnot(x)if(x,false,true)and(x,y)if(x,y,false)or(x,y)if(x,true,y)implies(x,y)if(x,y,true)=(x,x)true=(x,y)if(x,y,not(y))if(true,x,y)xif(false,x,y)yif(x,x,if(x,false,true))true=(x,y)if(x,y,if(y,false,true))not(x)if(x,false,true)and(x,y)if(x,y,false)or(x,y)if(x,true,y)implies(x,y)if(x,y,true)=(x,x)true=(x,y)if(x,y,not(y))if(true,x,y)xif(false,x,y)yif(x,x,if(x,false,true))true=(x,y)if(x,y,if(y,false,true))Marked_not(x)Marked_if(x,false,true)Marked_and(x,y)Marked_if(x,y,false)Marked_or(x,y)Marked_if(x,true,y)Marked_implies(x,y)Marked_if(x,y,true)Marked_=(x,y)Marked_if(x,y,not(y))Marked_=(x,y)Marked_not(y)Marked_=(x,y)Marked_if(x,y,if(y,false,true))Marked_=(x,y)Marked_if(y,false,true)