differential), times (multiply), cdot (center-dot), nothing (zero-width
space), approx (approximately equals), prime (prime), half (one-half),
partial (partial differential), inf (infinity), >> (much greater), <<
differential), times (multiply), cdot (center-dot), nothing (zero-width
space), approx (approximately equals), prime (prime), half (one-half),
partial (partial differential), inf (infinity), >> (much greater), <<