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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