# Polish notation (prefix notation)

Polish notation (prefix notation) is a mathematical notation in which operators precede their operands, in contrast to standard infix notation, in which operators are placed between operands. It is also known as normal Polish notation (NPN), Warsaw notation, Polish prefix notation or simply prefix notation.

Infix notation is the more common notation for arithmetic expressions. In infix notation, an operator is placed between its operands, e.g. 3 + 4. In contrast, Polish notation places operators before their operands, e.g. + 3 4.

Polish notation was invented by the Polish logician and mathematician Jan Ćukasiewicz. It is named after him, although it was independently invented by Frege and Peano. How do you prefix notation? To use prefix notation, you need to first understand the concept of operators and operands. Operators are the symbols that tell the computer what to do with the operands, which are the numerical values that the operators act on. In prefix notation, the operator is always written before the operands. For example, the addition operator (+) would be written before the two operands, like this: + 3 4. This would tell the computer to add the numbers 3 and 4 together.

### What are Polish notations examples?

Polish notation is a way of representing mathematical expressions in which the operators come before their operands. For example, the expression "3 + 4" would be written as "+ 3 4" in Polish notation.

There are many different variations of Polish notation, but they all follow the same basic principle. Some examples of Polish notation expressions are:

+ 3 4
- 5 6
* 7 8
/ 9 10

As you can see, the operators are always written first, followed by the operands. This can make Polish notation expressions easier to read and understand, as well as making them easier to parse mathematically.

##### What is the use of prefix notation?

In mathematics and computer science, prefix notation is a notation for writing expressions in which the operator is written before its operands.

An example of a prefix expression is +ab, which would be interpreted as "add a and b". In this case, the operator + is a prefix operator, and the operands a and b are both postfix operands.

Prefix notation is often used when writing arithmetic expressions, because it can eliminate the need for parentheses. For example, the expression (a+b)*c can be written as *+abc.

Prefix notation is also useful in computer programming, because it can be used to create expressions that are easier to parse. For example, most programming languages use infix notation (e.g. a+b), which can be difficult to parse. However, if the same expression is written in prefix notation (+ab), it can be much easier to parse.

##### How do I find the prefix and postfix?

There are two ways to find the prefix and postfix of a string:

1. Use the "find" function:

This function will return the position of the first occurrence of a substring in a string. The position will be given as an integer.

To find the prefix, simply pass the substring as the first argument and the string as the second argument. The function will return the position of the first occurrence of the substring in the string.

To find the postfix, simply pass the string as the first argument and the substring as the second argument. The function will return the position of the last occurrence of the substring in the string.

2. Use the "split" function:

This function will split a string into a list of substrings. The substrings will be separated by the given delimiter.

To find the prefix, simply pass the string as the first argument and the substring as the delimiter. The function will return a list containing the prefix and the rest of the string.

To find the postfix, simply pass the string as the first argument and the substring as the delimiter. The function will return a list containing the rest of the string and the postfix.

##### What would be the prefix notation for the given equation ?

( A +( b/c )*( d/e )- F? The answer to the question is as follows:

The prefix notation for the given equation is:

+(A/(*(b/c)(d/e))-F