每一个正规算子显而易见地是次正规的。

Every normal operator is trivially subnormal.

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尝试是引用光谱定理而得到正规算子恒有非平凡不变子空间的结论。

The cheapest way to get one is to invoke the spectral theorem and to conclude that normal operators always have non-trivial invariant subspaces.

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保留锥P为正规锥，将增算子A减弱为弱连续。空间E减弱为弱完备，在条件减弱的情况下，仍然得到了增算子不动点的存在性。

In this paper, we retains the cone P normal cone, increasing operator A weaken the weakly continuous operator, space E weaken the weak complete space.

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