61.5 Magma Rings modulo the Span of a Zero Element

  • IsElementOfMagmaRingModuloSpanOfZeroFamily( Fam ) C

    We need this for the normalization method, which takes a family as first argument.

  • IsMagmaRingModuloSpanOfZero( RM ) C

  • MagmaRingModuloSpanOfZero( R, M, z ) F

    Let R be a ring, M a magma, and z an element of M with the property that z \* m = z for all m Î M. The element z could be called a ``zero element'' of M, but note that in general z cannot be obtained as Zero( m ) for each m Î M, so this situation does not match the definition of Zero (see Zero).

    MagmaRingModuloSpanOfZero returns the magma ring R M modulo the relation given by the identification of z with zero. This is an example of a magma ring modulo relations, see Magma Rings modulo Relations.

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    GAP 4 manual
    February 2000