`expression``.sum(``exp``)`¶

`expression` + `exp`¶

An expression which denotes the sum (or disjunction) of both series.

Preconditions:

None

See also:

Examples¶

In [1]:

import vcsn
ctx = vcsn.context('lal_char, q')
exp = lambda e: ctx.expression(e)
exp('a*b') + exp('ab*')

Out[1]:

$a \, {b}^{*} + {a}^{*} \, b$

Of course, trivial identities are applied.

In [2]:

exp('<2>a') + exp('<3>a')

Out[2]:

$ \left\langle 5 \right\rangle \,a$

In [3]:

exp('<2>a') + exp('\z')

Out[3]:

$ \left\langle 2 \right\rangle \,a$