Ipso facto is Latin and is defined as by the fact.
If all squares are rectangles and all rectangles have four sides, this is an example of when a square has four sides ipso facto.
by that very fact
Origin of ipso factoClassical Latin
By the fact itself; by that very fact: An alien, ipso facto, has no right to a US passport.
Origin of ipso factoNew Latin ips&omacron; fact&omacron; : Latin ips&omacron;, ablative of ipse, itself + Latin fact&omacron;, ablative of factum, fact.
ipso facto - Legal Definition
As a matter of fact.