
theorem Th37:
  for L being non empty transitive reflexive RelStr, X be Subset of L holds
  ex_inf_of X,L iff ex_inf_of uparrow X,L
proof
  let L be non empty transitive reflexive RelStr, X be Subset of L;
  for x being Element of L holds x is_<=_than X iff x is_<=_than uparrow X
  by Th36;
  hence thesis by YELLOW_0:48;
end;
