OPTION ARITHMETIC ☆

`OPTION ARITHMETIC DECIMAL`
lets all numbers be decimal floating point.

`OPTION ARITHMETIC NATIVE`
lets all numbers be double precision floating point.
The precision is about 16 digits.
Although decimal fractions may have errors, computation is fast.

The scope of OPTION ARITHMETIC statement is the Program unit where it is written.
Program units that do not deliver or receive numbers may have different OPTION ARITHMETIC.
An OPTION statement is a declarative statement, which is not an object of the control.

Original Enhancements
`OPTION ARITHMETIC DECIMAL_HIGH`
Decimal 1000 digits operation. (Transcendental functions have the precision of 17 digits(last digit even).)
`OPTION ARITHMETIC COMPLEX`
Complex numbers
`OPTION ARITHMETIC RATIONAL`
Rational numbers of huge digits. (irrational functions have the precision of 17 digits(last digit even).)

(Note)
If a program unit has no OPTION ARITHMETIC statement, number manipulation obeys the designate on the Option Menu - Precision