		E01E	dot product for 2 vectors - gives scalar
				v1v2 = Σ(d= 1 to 2 or 3 : x1d*x2d)
		E129	cross product for 2 vectors - gives vector
				v1v2 = det(d=2 or 3 : d d reshape link nj vij)
				ni = unit orthogonal vector basis
∇		2207	gradient (nabla or del) of scalar field f - gives vector	
				v = Σ(i=1 to D : ∂/∂xi(f)*ni )
∇		combo	divergence (grad-dot) of vector field V - gives scalar
				∇V = Σ(i=1 to 2 or 3: ∂/∂xi(Vi) )
∇		combo	curl (grad-cross) of vector field v - gives vector
				∇V= det(i=1 to 3 : i i reshape link ni ∂/∂xi(V) vi ...)
				ni = unit orthogonal vector basis

∇′ 	gradient  in particle/system frame


r_hat			In Lucas's notation, an "^" or "hat" over a letter - denotes a unit vector in the direction of the vector
				represented by the letter, eg  r_h  (r in Lucas writing) means a unit vector in the direction of vector r.

⊥				perpendicular to

# [Howell 17Aug2015 -  in Lucas's "Universal force, volume 1" the variables t, c, n q are scalar, the rest are vector.  
 
|r - v*t|	In Lucas's book, this denotes the vector norm (usually written ||r - v*t||) rather than the absolute value of each component of a vector or matrix, as is the usual interpretation of |r - v*t|.   The single verticle bars do usually denote the norm on the one-dimensional vector spaces formed by the real or complex numbers, for example |-3| (absolute value)
	(see https://en.wikipedia.org/wiki/Norm_%28mathematics%29)


d[dt: x]				total   derivative of x with respect to t 
dp[dt: x]			partial derivative of x with respect to t 
d^n[dt^n: x]		nth total   derivative of x with respect to t 
dp^n[dt^n: x]		nth partial derivative of x with respect to t 
∫[ds: f]				indefinite integral of f with respect to s
∫[ds, a to b: f]	definite integral of f with respect to s, from a to b 
∮[ds: f(t)]			integral of f(t) over the closed [2D curve, 3D surface] S
∮[dl: f(l)]			closed-loop integral f(l) wrt dl (pathway)
∮[dl: f(l)]		closed-loop integral with dot product of  integranddl (eg in Green's theorem etc)

∫		222B	integral
∫c		222E	line integral closed 
∬s		222C	surface integral
∫∫∫v	2230	volume integral
△		25B3	delta (change)
∆		2206	delta (change)
∂		2202	partial deriv
√		221A	square root
∝		221D	proportional
∞		221E	infinity
≈		2248	approximately equal to
≠		2260	not equal to
==		2250	identically equal to (should be "=" with dot over)
∆=		225C	???   (should be "=" with dot over)
≤		2264	less than or equal to
≥		2265	greater than or equal to
⊥		22A5	perpendicular 

'		E094	prime often for RFp - particle reference frame
∘		221E
∈		2208	element of


Special note - the Unicode character for dotProduct has to be selected to show up in 
	[ ????????????????????
LibreWrite, pdf, kwrite, LibreCalc]
The character    (Ctrl+Shift+U+E01E) works well so far.