ASCII
angle
char cosd
decimal directiontime
floor
hex
intersectiontimes
jobname
known
length
makepath makepen mexp mlog
normaldeviate
oct odd
pencircle penoffset point postcontrol precontrol
reverse rotated
sind sqrt str subpath substring
totalweight turningnumber
uniformdeviate unknown
xpart xxpart xypart
ypart yxpart yypart

----------------------------------------------------

[
	["builtin", "ASCII"],
	["builtin", "angle"],
	["builtin", "char"],
	["builtin", "cosd"],
	["builtin", "decimal"],
	["builtin", "directiontime"],
	["builtin", "floor"],
	["builtin", "hex"],
	["builtin", "intersectiontimes"],
	["builtin", "jobname"],
	["builtin", "known"],
	["builtin", "length"],
	["builtin", "makepath"],
	["builtin", "makepen"],
	["builtin", "mexp"],
	["builtin", "mlog"],
	["builtin", "normaldeviate"],
	["builtin", "oct"],
	["builtin", "odd"],
	["builtin", "pencircle"],
	["builtin", "penoffset"],
	["builtin", "point"],
	["builtin", "postcontrol"],
	["builtin", "precontrol"],
	["builtin", "reverse"],
	["builtin", "rotated"],
	["builtin", "sind"],
	["builtin", "sqrt"],
	["builtin", "str"],
	["builtin", "subpath"],
	["builtin", "substring"],
	["builtin", "totalweight"],
	["builtin", "turningnumber"],
	["builtin", "uniformdeviate"],
	["builtin", "unknown"],
	["builtin", "xpart"],
	["builtin", "xxpart"],
	["builtin", "xypart"],
	["builtin", "ypart"],
	["builtin", "yxpart"],
	["builtin", "yypart"]
]

----------------------------------------------------

Checks for primitive METAFONT operations.