The first sign of syphilis is a small sore, called a chancre (SHANG-kur). The sore appears at the spot where the bacteria entered your body. While most people infected with syphilis develop only one chancre, some people develop several of them. The chancre usually develops about three weeks after exposure.
The colon is the symbol :. It is used in a number of different ways in mathematics. 1. To denote ratio or odds, as in 2:1 (voiced two to one). 2. To mean such that in constructions such as (voiced the set of numbers such that ). 3. To give a name to a map, e.g., (which is equivalent to the function notation ).
One of the symbols [ and ] used in many different contexts in mathematics. 1. Square brackets are occasionally used in especially complex expressions in place of (or in addition to) parentheses, especially as a group symbol outside an inner set of parentheses, e.g., .