Write b:
Notice that satisfies the following recurrence:
where just if .
NB: which are formulas of size (so, in particular, linear-size circuits).

Apr 10, 20261 min read
Write LEQn:{0,1}n×.{0,1}n→{0,1} b:
LEQn(x,y)=1⟺ number coded by x≤ number coded by yNotice that LEQn satisfies the following recurrence:
LEQ1(x,y)=¬x∨yLEQn+1(xxn+1,yyn+1)=⎩⎨⎧LEQn(x,y)∧NEQn(x,y)xn+1∧¬yn+1LEQn(x,y)otherwisewhere NEQn(x,y)=1 just if x=y.
NB: NEQn(x,y)=⋁i=1n(¬x1∧y1)∨(x1∧¬y1) which are formulas of size O(n) (so, in particular, linear-size circuits).
