Buerger's test Buerger's test Buerger's test is used in an assessment of arterial sufficiency. The "vascular angle", which is also called "Buerger's angle", is the angle to which the leg has to be raised before it becomes pale, whilst lying down. In a limb with a normal circulation the toes and sole of the foot, stay pink, even when the limb is raised by 90 degrees. In an ischaemic leg, elevation to 15 degrees or 30 degrees for 30 to 60 seconds may cause pallor. (This part of the test checks for "elevation pallor".) A vascular angle of less than 20 degrees
Less-than sign is used to denote the beginning of a heredoc statement (where OUTPUT is an arbitrary named variable.) In Bash, «<word is used as a "here string", where word is expanded and supplied to the command on its standard input, similar to a heredoc. The less-than sign plus the equals sign (<=) is used for an approximation of the less-than-or-equal-to sign (≤). ASCII does not have a less-than-or-equal-to sign, but Unicode defines it at code point U+2264. In BASIC, Lisp-family languages, and C-family languages (including Java and C++), operator <= means "less than or equal to". In Sinclair BASIC it is