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5.1.34 fetch
Syntax:
fetch ( ring_name, name )
Type:
- number, poly, vector, ideal, module, matrix or list
(the same type as the second argument)
Purpose:
- maps objects between rings.
fetch is the identity map between rings and qrings,
the i-th variable of the source ring is mapped to the i-th
variable of the basering. The coefficient fields must be compatible.
(See map for a description of possible mappings between
different ground fields).
fetch offers a convenient way to change
variable names or orderings, or to map objects from a ring to a quotient
ring of that ring or vice versa.
Note:
- Compared with
imap , fetch uses the position of the ring
variables, not their names.
Example:
See
imap;
map;
qring;
ring.
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