VXL reference: reserved words
The following identifiers are reserved and may not name a param, let, table or at_each variable; using one is VXL-N103. They are the coordinates x, y and z, the constant pi, the boolean literals and operators, the unit suffixes and every built-in function name (38 words, in compiler order).
x, y, z, pi, true, false, and, or, not, if, lookup, mm, deg, abs, min, max, clamp, sqrt, cbrt, sin, cos, tan, asin, acos, atan, atan2, exp, ln, gauss, hypot, floor, ceil, round, fract, mod, sign, smoothstep, lerp