Section KNASTER_TARSKI. (* Reference: "https://www.cs.utexas.edu/users/misra/Notes.dir/KnasterTarski.pdf" written by Jayadev Misra *)
Context {D : Type} {PROSET : isProset D} {COLA : isCola D (PROSET := PROSET)}.

Theorem KnasterTarski_2nd (f : D -> D)
(f_isMonotonic : isMonotonic1 f)
: { gfp_f : D | is_supremum_of gfp_f (postfixedpointsOf f) /\ is_gfpOf gfp_f f }.