In this paper we continue the study of Girard's Linear Logic and intro
duce a new Linear Logic with modalities. Our logic describes not only
the consumption, but also the presence of resources. We introduce a ne
w semantics and a new calculus for this logic. In contrast to the resu
lts of Lincoln et al. [7] and Kanovich [4] about the NP-completeness o
f the problem of the construction of a proof for a given sequent in th
e multiplicative fragment of Girard's Linear Logic, we present here a
non-exponential algorithm to construct a proof for a given sequent and
a given point of a given model in our Linear Logic.