Commands

Note that n represents the only argument of a function of arity 1, a and b represent the arguments of function of arity 2. Here is a list of Triangularity commands:

Symbol	Function	Notes / Usage Rules
!	Logical negation of n.	–
"	Begin and end a string literal.	The whole string must be on the same line. There cannot be any "s in a string literal.
)	Push a 0 onto the stack.	Precedes an integer literal.
+	Addition. Return a + b.	–
/	Division. Return b / a.	–
<	Check whether b < a.	–
=	Check whether b equals a.	–
>	Check whether b > a.	–
@	Increment. Return n + 1.	–
^	Exponentiation. Push ba.	–
_	Negative. Return - n.	–
`	Cast to string. Return str(n).	–
C	Count the occurrences of b in a.	–
E	Evaluate n. eval in Python.	–
I	Input at index n.	Modular, 0-based.
J	Join a with separator b.	–
L	Length. Return len(n).	–
O	Sort. Return an ordered version of n.	–
R	Reverse. Push n reversed.	–
c	Chr (from ASCII value to character). Push chr(n).	Uses Python's built-in.
d	Divisors.	Only includes positive divisors.
e	Dumps all contents separately onto the stack.	–
f	Cast to an integer. Trims decimals.	–
h	Head. Return b[:a].	0-based.
i	Read all STDIN.	–
l	Return the indices of b where a occurs.	0-based.
m	Indexing. Return b[a % len(b)].	Modular, 0-based.
o	Ord (from character to ASCII value). Push ord(n).	Uses Python's built-in.
p	Check whether n is prime.	–
r	List the integers in the range [b, a).	–
t	Tail. Return b[a:].	0-based.
u	Sum. Return the sum of n.	–
w	Wrap into an array. Return [n].	–

Stack Manipulation

Symbol	Function
D	Duplicate. Push n, n.
P	Pop. Discard n.
W	Wrap stack to an array. Return [stack].
s	Swap. Push b, a.