The system of all congruences of an algebra (A, F) forms a lattice, denoted \({{\,\mathrm{Con}\,}}(A, F)\). Further, the system of all congruence lattices of all algebras with the base set A forms a lattice \(\mathcal {E}_A\). We deal with meet-irreducibility in \(\mathcal {E}_A\) for a given finite set A. All meet-irreducible elements of \(\mathcal {E}_A\) are congruence lattices of monounary algebras. Some types of meet-irreducible congruence lattices were already described. In the case when a monounary algebra (A, f) is connected, we prove necessary and sufficient condition under which \({{\,\mathrm{Con}\,}}(A, f)\) is \(\wedge \)-irreducible.

代数（A，  F）的所有等价度的系统形成一个晶格，表示为\（{{\，\ mathrm {Con} \，}}（A，F）\）。此外，具有基集A的所有代数的所有全等格的系统形成一个格\（\ mathcal {E} _A \）。对于给定的有限集合A，我们处理\（\ mathcal {E} _A \）中的遇见不可约性。\（\ mathcal {E} _A \）的所有满足不可约元素都是一元代数的全等格。已经描述了一些类型的满足不可约的全等格。在一元代数（A，  f）相连，我们证明\（{{\，\ mathrm {Con} \，}}（A，f）\）是\（\ wedge \）-不可约的充要条件。