Arithmetic
The Relevance language includes the typical binary mathematical functions, including addition, subtraction, multiplication, division and modulo.
Q: 21 mod 5
A: 1
Returns the integer corresponding to 21 modulo 5.
Q: 36*month/2
A: 1 years, 6 months
Multiplies and divides months resulting in a ‘month and year’ type.
Q: 2+3
A: 5
Adds integers together to produce a sum.
Q: current month + 2*month
A: November
Adds two months to the current month (in this case, September).
Q: december - current month
A: 3 months
Subtracts the current month (1-12) from December (12) to produce a ‘number of months’ type.
A few operators in the language are unary (requiring only one argument), such as negation:
Q: -(3*5)
A: -15
As expected, this minus sign negates its argument (the product in parentheses).
There is another "arithmetic" symbol, the ampersand (&). This is the concatenation operator that joins strings:
Q: "now" & "then"
A: nowthen
It’s also used to create time ranges:
Q: now & day
A: Sat, 21 Oct 2006 21:55:28 -0400 to Sun, 22 Oct 2006 21:55:28 -0400