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7.2.2.1 map declarations (plural)
- Syntax:
map name = preimage_ring_name , ideal_expression ;
map name = preimage_ring_name , list_of_poly_and_ideal_expressions ;
map name = map_expression ;
- Purpose:
- defines a ring map from
preimage_ring to basering.
Maps the variables of the preimage ring to the generators of the ideal.
If the ideal contains less elements than the number of variables in the
preimage_ring , the remaining variables are mapped to 0.
If the ideal contains more elements, extra elements are ignored.
The image ring is always the current basering.
For the mapping of coefficients from different fields see map (plural).
- Default:
- none
- Note:
- There are standard mappings for maps which are close to the identity
map:
fetch (plural) and imap (plural) .
The name of a map serves as the function which maps objects from the
preimage_ring into the basering. These objects must be defined
by names (no evaluation in the preimage ring is possible).
- Example:
See
fetch (plural);
ideal expressions (plural);
imap (plural);
map (plural);
ring (plural).
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