If the document opened in the IFRAME does not have any targets set, then all those links will open in the same iframe as the parent document. You can use this feature to make links in one IFRAME change the contents of another IFRAME on the same page. IFrames and Security. The IFRAME element, by
Sigma notation, often referred to as summation notation, can be used in many common situations. For example, it can be used to calculate the sum of deposits for a bank account. Banks add together all deposits and withdrawals to determine the current balance.
Sigma (upper-case Ï, lower-case Ï, lower-case in word-final position Ï; Greek: ÏÎ¯Î³Î¼Î±) is the eighteenth letter of the Greek alphabet. In the system of Greek numerals, it has a value of 200. When used at the end of a word (when the word is not all caps), the final form (Ï) is used, e.g. á½Î´ÏÏÏÎµÏÏ (Odysseus); note the two sigmas in the center of the name, and the word-final sigma at the end. 1  1 History.  1.1 Etymology.