Add support for component-aliases in vector.Namely
Base voronoi.Catchment on set.

It's a set of points, to which we can add new members, albeit augmented with
some special features.
Make voronoi.Catchment cope with zero width in some dimensions.

If all the points have the same component for some co-ordinate, ignore that
co-ordinate for splitting of boxes.
Made Quantity.fromDecimal()'s decimals default to 0.

This proves useful in practice.  Adjusted documentation to match and tweaked a
sentence later in the same doc-string.
Doc-string tidying in study.value.quantity.

Mostly reflow.  Added missing \n at ends of some.
Cope with vectors, hide Prodict, fixed a typo.

Suitable tunnelling makes it possible to del Prodict at the end.
There was petty a typo in Quantity.observe()'s doc-string.
Have __mul__ and __rdiv__ cope when other is a study.maths.vector.Vector, by
deferring suitably to its multiplication.  Assumes any tuple is in fact some
kind of a vector; that may need to change once I have a common base-class for
sparse (dictionary) vectors and full (duple) ones.
Support negation; and some fixes in Namely.

Added Vector.__neg__().  Namely's check against None entries ran afoul of "is
in" tests using equality and somethings not liking to be compared vs None; so
fix to an any(x is None for x in seq) test instead.  The Namely.__vector__()
wanted to * its parameter, which is sometimes an iterator; so tuple() it first.
Added Quantity.parseDecimal() and fixed up some documentation.

Make clear, where each convenience constructor's doc-string talks about
forwarding further args, how the first positional one, if any, shall be
read.  Add a convenience constructor that parses a decimal float.
Complicated seismic details, added archaea.Krakatoa

Changed energies' .seismic to a sub-object with attributes matching those of
archaea.Magnitude; and recoded the latter (as a class) so that one can
round-trip between the two (which requires going via .evaluate() when
Magnitude's methods are called on a Quantity).

Added Krakatoa as a unit of energy on such a scale as to have climactic
impact.  Also corrected my (apparently) mistaken supposition that megatons use
the US ton; Wikipedia assures me it's the metric tonne.
Clarification of Permutation.iterator's Theory doc.
Clarify doc of Iterable.cartesian and add examples.
Added Permutation.isa() and simplified some code.

Permutation's .__new__() was already checking validity, making some defensive
older code redundant.  Replaced the old check with .isa(), which is a little
more exacting.  Amended assorted documentation to match.
Added Tensor.antisymmetric() constructor.

This provides the globally antisymmetric tensor on a given space, with rank
equal to the space's dimension.
Optimisation of Vector.__pow__().

Avoid squaring self on the last iteration.
Make Tuple redirect __iterable__ as a method, not an assignment.

Assigning __iterable__ = __tuple__ means that derived classes (unless they do
the same) inherit Tuple.__tuple__ as their .__iterable__; but, if they've
overridden __tuple__, they want the replacement used for __iterable__, too.
Document Iterable.reduce() and handle init better.

Also @lazyprop mean and geomean, like max and min, on ReadOnlySeq.  For sum and
product, use reduce()'s default for init, so as to avoid having to pass them a
suitable additive identity when it shouldn't be needed, instead of supplying
defaults of our own; but still let the caller pass init if wanted.  Make mean()
fussy about preserving wholeness, when it can.
Make Tuple propagate itself onto slices.

Plus a slight correction in List's comment, where it does the same.
More iterator-friendly version; and improved Dict.cartesian()'s doc.

Make less of the old functional builtins, in favour of list comprehensions and
iterators.  Tweaked @iterable to be able to apply to a static method with no
args.  Renamed Dict.cartesian()'s arglist to make the doc-string read better -
once I'd fixed some infelicities in it (no longer an instance method, so no self
to prepend to the *others) - and gave an example of using this method.
Pertinent link from irregular web-comic, for year.
Neglected to mention photon, as well as neutrino, as light particles.