We extend the theory of unified correspondence to a very broad class of logics with algebraic semantics given by varieties of normal lattice expansions (LEs), also known as 'lattices with operators'. Specifically, we introduce a very general syntactic definition of the class of Sahlqvist formulas and inequalities, which applies uniformly to each LE-signature and is given purely in terms of the order-theoretic properties of the algebraic interpretations of the logical connectives. Together with this, we introduce a variant of the algorithm ALBA, specific to the setting of LEs, which effectively computes first-order correspondents of LE-inequalities, and is guaranteed to succeed on a wide class of inequalities (the so-called inductive inequalities) which significantly extend the Sahlqvist class. Further, we show that every inequality on which ALBA succeeds is canonical. The projection of these results yields state-of-the-art correspondence theory for many well known substructural logics, such as the Lambek calculus and its extensions, the Lambek-Grishin calculus, the logic of (not necessarily distributive) de Morgan lattices, and the multiplicative-additive fragment of linear logic. theoretical framework which would provide a mathematically grounded way to compare (hierarchies of) Sahlqvisttype classes belonging to different logical settings. 1 Along with this lack of uniformity, each Sahlqvist-type results is tied to a particular choice of relational semantics for the relevant logic. Such a choice could be motivated by the fact that a logic has a uniquely established set-based semantics, but for many logics, like substructural logics, this is not the case. Hence, it is desirable to have a modular Sahlqvist theory that would distinguish core characteristics from incidental details relating to a particular choice of relational semantics.A theory which subsumes the previous results and which satisfies the desiderata of uniformity and modularity is currently emerging, and has been dubbed unified correspondence [7]. It is built on duality-theoretic insights [11] and uniformly exports the state-of-the-art in Sahlqvist theory from normal modal logic to a wide range of logics which include, among others, intuitionistic and distributive lattice-based (normal modal) logics [10], non-normal (regular) modal logics of arbitrary modal signature [39], hybrid logics [14], and mu-calculus [5,6].The breadth of this work has also stimulated many and varied applications. Some are closely related to the core concerns of the theory itself, such as the understanding of the relationship between different methodologies for obtaining canonicity results [38,9], or of the phenomenon of pseudo-correspondence [12]. Other, possibly surprising applications include the dual characterizations of classes of finite lattices [20], and the identification of the syntactic shape of axioms which can be translated into analytic structural rules of a proper display calculus [28]. Finally, the insights of unified correspondence theory have made it possible ...