Two equivalent formulations of the binary search algorithm

First version:
procedure binary search (: integer, : increasing integers)


while
 
 if then
 else
if then location
else location
return location

Second version:
procedure binary search (: integers, , : increasing integers)
if then
 return
else if ( and ) then
 return binary search()
else if ( and ) then
  return binary search()
else return 0
{output is location of in if it appears; otherwise it is 0}