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QQEmbeddingHom

returns the homomorphism QQ --> R

Syntax
QQEmbeddingHom(R: RING): RINGHOM

Description
This function returns the homomorphism QQ --> R . This is useful for changing the ring of coefficients.

NOTE: this is a partial homomorphism when R has finite characteristic.

Example
/**/  use QQxy ::= QQ[x,y];
/**/  f := (2/3)*x +5*y;

/**/  FFpxy ::= ZZ/(101)[x,y];
/**/  QQEmbeddingHom(FFpxy) (LC(f));
-33
/**/  phi := PolyRingHom(QQxy, FFpxy, QQEmbeddingHom(FFpxy), indets(FFpxy));
/**/  phi(f);
-33*x +5*y

/**/  RRxy := NewPolyRing(NewRingTwinFloat(64), "x,y");
/**/  phi := PolyRingHom(QQxy, RRxy, QQEmbeddingHom(RRxy), indets(RRxy));
/**/  phi(f);
2/3*x +5*y

See Also