Prooftoys syntax quick reference

For more complete and precise information, see the full reference.

Logic operators

Concept English Symbol Text entry
Untrue not not not
At least one true or | |
Both true and & &
Conditional implies => =>
Equivalent == ==
True for all for all forall forall
True for some exists exists exists

Precedence of infix operators in order from highest to lowest, is &, |, =>, ==.

The rest are functions, which bind tighter than infix operators, so not a & b means the same as (not a) & b.

Basic math

Basic binary math operations are: +, -, *, /, ^ (exponentiation). Exponentiation has the highest precedence, followed by multiplication and division, followed by addition and subtraction. The negative of a number is expressed by the function neg, which displays as a prefix -.

Variables and constants

Variable names have a single alphabetic character, such as x or A. The single letter may be followed by digits or a single underscore and then digits. A variable name may also begin with $, but these are mainly intended to be introduced by the system.

Names with multiple alphabetic characters are always constants, and may also include digits.

The characters ".", “,”, “(”, “{”, “[" are reserved as parts of the syntax. Sequences of characters that are not letters or digits and not reserved for the syntax are also constants.