Question: What gun developed in Nazi Germany and used in WWII did the M56 submachine gun clone?
Context: The Jatimatic is a Finnish 9 mm submachine gun developed in the late 1970s and early 1980s by Jali Timari.  The submachine gun made its debut in 1983.  The Jatimatic was manufactured in very limited numbers (approx. 400) initially by Tampereen Asepaja Oy of Tampere and later—Oy Golden Gun Ltd (as the GG-95 PDW, re-introduced unsuccessfully in 1995).  The firearm was designed primarily for police, security forces and armored vehicle crews.  It was never adopted into service by the Finnish Defence Forces, although the later GG-95 PDW version was tested by the FDF in the 1990s; the conclusion of the tests was that the GG-95 was not suitable as a service weapon. MCEM-2 (Machine Carbine Experimental Model 2) submachine gun was produced only in prototype form, but was one of the very first submachine guns to combine wrap-around bolt and magazine in pistol grip, features later copied in the Czechoslovak Sa vz.  23, Israeli Uzi and a great number of other submachine guns.  MCEM-2 was the second prototype in a line of experimental submachine guns, designed in Britain in 1944.  It was envisioned as a possible replacement for the STEN submachine gun then in service.  The MCEM-2 was developed by Jerzy Podsedkowski, a Polish constructor involved in work on Vis and Mors, who fled from occupied Poland to Britain.  It is believed that prototypes of MCEM-2 were made before the end of WW2, and its derivatives MCEM-4 and MCEM-6 were tested soon after the war.  The latter modifications differed mostly in adoption of the rate-reducing mechanism, incorporated into trigger unit; the rate of fire therefore was decreased from 1000 to more realistic 600 rounds per minute.  Nevertheless, neither prototype was found suitable for adoption, and several years later British army adopted a more conventional submachine gun, the Sterling-Patchett. The Arsenal M23 submachine gun (Estonian: "Arsenali püstolkuulipilduja" ) (also known as Arsenal Tallinn) was an Estonian submachine gun from 1926 through 1935.  These submachine guns were designed and produced in the Estonian military equipment factory "Arsenal" in Karjamaa, Tallinn, but production was not more than 600 units.  The weapon was chambered for the 9x20 mm semi-rimmed Browning cartridge to be compatible with ammunition for the Browning FN M1903 pistol which had been adopted by the Estonian Army.  It operated on the blowback system and was essentially similar to the MP18.1; having a wooden stock, slotted barrel jacket, and horizontal left side magazine feed.  A uniquely slender 40 round single column box magazine led to frequent cartridge feeding problems; and cooling fins which were machined lengthwise along the barrel to promote cooling air flow when firing (similar to the Lewis machine gun), unnecessarily complicated production.  It was used by the combat support units of the Border Guard, the Estonian Defence League and the Estonian Defence Forces.  The Arsenal submachine gun was replaced in Estonian service by the Finnish Suomi KP/-31 submachine gun in 1938.  The Estonian Army sold a few samples to Latvia and all of the remainder found their way to Republican forces during the Civil War in Spain. The MP 40 ("Maschinenpistole 40") was a submachine gun chambered for the 9×19mm Parabellum cartridge.  It was developed in Nazi Germany and used extensively by the Axis powers during the Second World War. The Rexim-Favor submachine gun is a Swiss submachine gun developed by the Rexim Small Arms Company of Geneva in 1953.  Originally known as the 'Favor', it received very little sales or use, but has become of note today for being the base of props used in the science fiction films "Star Wars" and "Alien". The Vityaz-SN is a 9×19mm Parabellum submachine gun developed in 2004 by Izhmash.  It is based on the AK-74 rifle and offers a high degree of parts commonality with the AK-74.  It is the standard submachine gun for all branches of the Russian military and police forces. The UMP ("Universale Maschinenpistole", German for "Universal Submachine Gun") is a submachine gun developed and manufactured by Heckler & Koch.  The UMP has been adopted by various agencies such as the U.S. Customs and Border Protection.  Heckler & Koch developed the UMP as a lighter and cheaper successor to the MP5, though both remain in production. The CF05 () submachine gun developed by Chongqing Changfeng in early 1990s in response to China's demand for a new submachine gun design.  It was developed by the same team who designed the QSZ-92 pistol, which is now the main pistol used by PLA and PAP.  CF05 design is chambered for 9×19mm Parabellum ammunition, used internationally for most pistols and sub machine guns used by armed forces and law enforcement. The Hyde-Inland M2 was a United States submachine gun design submitted for trials at Aberdeen Proving Ground in February, 1941.  Work was undertaken by General Motors Inland Manufacturing Division to develop workable prototypes of George Hyde's design patented in 1935.  The model first submitted for trials in April 1942 was designated the "Hyde-Inland 1".  Trials revealed the design was superior to the M1 submachine gun in mud and dirt tests, and its accuracy in full-automatic firing was better than any other submachine gun tested at the time.  An improved "Hyde-Inland 2" was designated U.S. Submachine gun, Caliber .45, M2 as a substitute standard for the M1 Thompson in April, 1942.  As Inland's manufacturing capacity became focused on M1 carbine production, the US Army contracted M2 production to Marlin Firearms in July, 1942.  Marlin began production in May 1943.  Marlin's production failed to match the trials prototype performance; and Marlin's original contract for 164,450 M2s was canceled in 1943 upon adoption of the M3 submachine gun.  The M2 is chambered for the .45 ACP cartridge and used the same 20- or 30-round magazine as the Thompson.  Its cyclic rate of fire is 570 rounds per minute.  None of the approximately 400 manufactured were issued by any branches of the United States military. The M56 submachine gun is a Yugoslavian submachine gun chambered in 7.62×25mm Tokarev, designed for use with the Yugoslav People's Army.  Initially a state-funded product, it was later produced by Zastava Arms and saw use in a number of conflicts following the breakup of former Yugoslavia.  The M56 is a clone of the MP 40 submachine gun used by Nazi Germany, easily distinguished from the MP 40 by its increased length and curved magazine.
Answer: MP 40