Option variable
assumescalarDefault value: true
assumescalar helps govern whether expressions expr
for which nonscalarp (expr) is false
are assumed to behave like scalars
for certain transformations.
Let expr represent any expression other than a list or a matrix,
and let [1, 2, 3] represent any list or matrix.
Then expr . [1, 2, 3] yields [expr, 2 expr, 3 expr]
if assumescalar is true, or scalarp (expr) is
true, or constantp (expr) is true.
If assumescalar is true, such
expressions will behave like scalars only for commutative
operators, but not for noncommutative multiplication ..
When assumescalar is false, such
expressions will behave like non-scalars.
When assumescalar is all,
such expressions will behave like scalars for all the operators listed
above.