Professional foul Football League, recommended in 1982 that any offence that denies the attacking player an obvious scoring opportunity should be deemed "serious foul play" by English referees and would therefore receive a red card, in order to deter offenders. The subcommittee produced several suggestions, including making the professional foul a mandatory red card offence, which they submitted to the IFAB for consideration. All the suggestions were defeated. The rule was finally fixed into the Laws of the Game by IFAB in 1990 and referees were instructed by FIFA for the 1990 World Cup to send off players for a professional foul.
Gain scheduling variables. A relatively large scope state of the art about gain scheduling has been published in (Survey of Gain-Scheduling Analysis & Design, D.J.Leith, WE.Leithead). Gain scheduling In control theory, gain scheduling is an approach to control of non-linear systems that uses a family of linear controllers, each of which provides satisfactory control for a different operating point of the system. One or more observable variables, called the "scheduling variables", are used to determine what operating region the system is currently in and to enable the appropriate linear controller. For example, in an aircraft flight control system, the altitude and Mach