A tiny language with as few features as I could manage. (but with syntax sugar to spare!)
main() {
console << "Hello"
}
f(x, y) = 10sin(x/10) - y
inflection(x, y) {
r = f(x + 0.5, y) > 0
l = f(x - 0.5, y) > 0
u = f(x, y + 0.5) > 0
d = f(x, y - 0.5) > 0
return r != l | u != d
}
size = 30
main() {
for (y, -size..size) {
for (x, -size..size) {
console << if (inflection(x, y)) "X"
elseif (x == 0 & y == 0) "+"
elseif (x == 0) "-"
elseif (y == 0) "|"
else " "
}
console << "\n"
}
}