for the remaining operators. Syntax Relational operators are also used in technical literature instead of words. Relational operators are usually written in infix notation, if supported by the programming language, which means that they appear between their operands (the two expressions being related). For example, an expression in Python will print the message if the x is less than y: if x < y: print("x is less than y in this example") Other programming languages, such as Lisp, use prefix notation, as follows: (>= X Y) Operator chaining In mathematics, it is common practice to chain relational operators, such as in 3 < x < y < 20 (meaning 3 < x and x < y and y < 20). The syntax is clear since these relational operators in mathematics are transitive. However, many recent programming languages would see an expression like 3 < x < y as consisting of two left (or right-) associative operators, interpreting it as something like (3 < x) < y. If we say that x=4, we then get (3 < 4) < y, and evaluation will give true < y which generally does not make sense. However, it does compile in C/C++ and some other languages, yielding surprising result (as true would be represented by the number 1 here). It is possible to give the expression x < y < z its familiar mathematical meaning, and some programming languages such as Python and Raku do that. Others, such as C# and Java, do not, partly because it would differ from the way most other infix operators work in C-like languages. The D programming language does not do that since it maintains some compatibility with C, and "Allowing C expressions but with subtly different semantics (albeit arguably in the right direction) would add more confusion than convenience". Some languages, like Common Lisp, use multiple argument predicates for this. In Lisp (<= 1 x 10) is true when x is between 1 and 10. Confusion with assignment operators Early FORTRAN (1956–57) was bounded by heavily restricted character sets where = was the only relational operator available. There were no < or > (and certainly no ≤ or ≥). This forced the designers to define symbols such as .GT., .LT., .GE., .EQ. etc. and subsequently made it tempting to use the remaining = character for copying, despite the obvious incoherence with mathematical usage (X=X+1 should be impossible).