4.3.1.1 Morphism Objects

class Morphism
Morphism( parent, f, [f_inverse=None])

The first argument f is a function or class with a call method (of one argument) that takes objects in domain and returns objects in codomain. The Map object, when called with argument x, tries to coerce it into the domain, if possible, and raises an error if it is not.

Instances of class Morphism have the following methods (in addition to inherited methods and special methods):

category,$  $ codomain,$  $ domain,$  $ is_endomorphism,$  $ parent

Instances of class Morphism also have the following special methods:

__add__,$  $ __call__,$  $ __cmp__,$  $ __invert__,$  $ __mul__,$  $ __pow__,$  $ __repr__,$  $ __sub__,$  $ _add_function,$  $ _mul_function,$  $ _sub_function

Further documentation:

__mul__( other)

The multiplication * operator is operator composition. Thus if $ s$ and $ t$ are Hecke operators, then $ (s*t)(x) = s(t(x))$ .

Note that if the morphisms are defined using matrices, then this is the reverse of matrix multiplication, since matrices act from the right.

INPUT:
    self -- Morphism
    other -- Morphism

OUTPUT:
    The morphism $x \mapsto self(other(x))$.

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