We begin with proving a formula relating the Hilbert series of a graded algebra $A$ and the Poincare series for $A$ in two variables using the existence of a graded minimal resolution of the field $k$ over $A$. This gives the Froberg formula in the case where the bigraded $Tor^A(k,k)$ is concentrated on the diagonal, which we take as definition of $A$ being ``Koszul". We look at a resolution in the commutative case obtained from the Koszul complex in the ``trivially Golod" case, which means that there are cycles that represent the homo\-logy of the Koszul complex and multiply to zero. The algebra structure of $Ext_A(k,k)$ is introduced in different ways. Its subalgebra generated by the one-dimensional elements is by definition the ``Koszul" dual of $A$. This is studied by means of the dual of the bar-complex. We define the ``generalized Koszul complex" and construct a minimal resolution in the case where the cube of the augmentation ideal of $A$ is zero. This is similar to the trivially Golod case above, but $A$ does not need to be commutative. The above results are at least 45 years old and most of it can be found in my thesis [?].

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