1 | | To summarize, there are at least 3 sources for `I`: `sage.rings.imaginary_unit`, `sage.symbolic.constants`, `sage.symbolic.expression`. All yield an `sage.symbolic.expression.Expression`, but only the first one gives the same `I` as the Python variable predefined in the interactive shell. |

| 1 | To summarize, there are at least 3 sources for `I`: `sage.rings.imaginary_unit`, `sage.symbolic.constants`, `sage.symbolic.expression`, but only the first one gives the same `I` as the Python variable predefined in the interactive shell. Moreover, we have |

| 2 | {{{ |

| 3 | sage: I.parent() |

| 4 | Number Field in I with defining polynomial x^2 + 1 with I = 1*I |

| 5 | sage: from sage.symbolic.constants import I as I1 |

| 6 | sage: I1.parent() |

| 7 | Symbolic Ring |

| 8 | sage: from sage.symbolic.expression import I as I2 |

| 9 | sage: I2.parent() |

| 10 | Symbolic Ring |

| 11 | sage: I2 is I1 |

| 12 | True |

| 13 | }}} |