a probability of at least p. In (Hanson, 1994), a
timed probabilistic concurrent computation tree logic
(TPCTL) is introduced and investigated. In (Baier and
Kwiatkowska, 1998), probabilistic branching time
logics (PBTL and PBTL
∗
) are introduced based on the
probabilistic temporal logics TPCTL, PCTL, pCTL,
and pCTL
∗
, and model-checking algorithms based on
PBTL and PBTL
∗
are proposed to automatically ver-
ify randomized distributed systems. In (Ognjanovic
et al., 2011), a propositional discrete probabilistic
branching temporal logic (pBTL) is developed by ex-
tending CTL
∗
. There are two types of novel probabil-
ity operators in pBTL: P
p
≥r
and P
s
≥r
, where P
p
≥r
α im-
plies that the probability that α holds on a randomly
chosen branch is at least γ, and P
s
≥r
α means that the
probability that α holds on a particular branch is at
least γ. In (Ognjanovic et al., 2012), a propositional
probabilistic logic with discrete linear time is devel-
oped to handle the clinical reasoning with respect to
evidence. More recent developments in probabilistic
model checking based on probabilistic temporal log-
ics are reported in (Baier et al., 2018).
2.2 Inconsistency-tolerant Temporal
Logics
In comparison with the standard non-paraconsistent
temporal logics CTL
∗
, CTL, and LTL, inconsistency-
tolerant (paraconsistent) logics can be appropri-
ately used in inconsistency-tolerant situations (Priest,
2002; da Costa et al., 1995; Wansing, 1993). Typ-
ical examples of non-temporal paraconsistent logics
include Belnap and Dunn’s useful four-valued logic
(Belnap, 1977b; Belnap, 1977a; Dunn, 1976) and
Nelson’s paraconsistent four-valued logic (Almukdad
and Nelson, 1984; Nelson, 1949). Combining these
logics with CTL
∗
, CTL, and LTL has led to the in-
troduction of various inconsistency-tolerant tempo-
ral logics, and inconsistency-tolerant versions (exten-
sions) of CTL, CTL
∗
, and LTL have been developed
by many researchers.
The multi-valued computation tree logic (χCTL)
was introduced by Easterbrook and Chechik (East-
erbrook and Chechik, 2001) as the base logic for
multi-valued model checking, the first framework for
inconsistency-tolerant model checking. The quasi-
classical temporal logic (QCTL) was introduced by
Chen and Wu (Chen and Wu, 2006) to verify in-
consistent concurrent systems using inconsistency-
tolerant model checking. The paraconsistent full
computation tree logic (4CTL
∗
) was proposed by
Kamide (Kamide, 2006a) to obtain a logical founda-
tion for inconsistency-tolerant model checking. The
paraconsistent linear-time temporal logic (PLTL)
was introduced by Kamide and Wansing (Kamide
and Wansing, 2011) to obtain a cut-free and com-
plete Gentzen-type sequent calculus. The alternative
paraconsistent computation tree logic (PCTL) was
introduced by Kamide and Kaneiwa (Kamide and
Kaneiwa, 2010; Kaneiwa and Kamide, 2011b) and
offered an alternative inconsistency-tolerant model
checking framework. Kamide (Kamide, 2015) intro-
duced the sequence-indexed paraconsistent computa-
tion tree logic (SPCTL), which can be obtained from
the CTL by adding the paraconsistent negation con-
nective, ∼, and a sequence modal operator, [b]. This
logic was used to verify clinical reasoning through
inconsistency-tolerant hierarchical model checking.
Kamide and Endo (Kamide and Endo, 2018) re-
cently developed pCTL and pLTL, which are alter-
native refined versions of the paraconsistent tempo-
ral logics PCTL and PLTL, respectively, to obtain
various simple and efficient translation methods for
inconsistency-tolerant model checking. These alter-
native refined logics adopt a simple single-satisfaction
relation. The alternative version of PCTL is pCTL,
which has the same name as the probabilistic com-
putation tree logic. Whereas PLTL (Kamide and
Wansing, 2011), PCTL (Kamide and Kaneiwa, 2010;
Kaneiwa and Kamide, 2011b), 4CTL
∗
(Kamide,
2006a), and SPCTL (Kamide, 2015) have two types
of dual-satisfaction relations, |=
+
(verification or jus-
tification) and |=
−
(refutation or falsification), pCTL
and pLTL (Kamide and Endo, 2018) have a simple
single-satisfaction relation, |=
∗
, which is highly com-
patible with the standard single-satisfaction relations
of LTL, CTL, and CTL
∗
. The single-satisfaction re-
lation can provide simple proofs for embedding theo-
rems, and the connective ∼ can be formalized simply
and handled uniformly.
To deal with open, large, and complex concurrent
systems, such as cloud-based systems and web appli-
cation systems, it is necessary to have extended log-
ics with model checking frameworks that can also si-
multaneously handle both inconsistency-tolerant and
probabilistic reasoning. To this end, in (Kamide
and Koizumi, 2015; Kamide and Koizumi, 2016), a
partial solution was obtained (i.e., an inconsistency-
tolerant extension of the probabilistic computation
tree logic, pCTL, was developed). The paraconsis-
tent probabilistic computation tree logic (PpCTL),
which can be obtained from the probabilistic compu-
tation tree logic, pCTL, by adding a paraconsistent
negation connective ∼, was constructed in (Kamide
and Koizumi, 2015; Kamide and Koizumi, 2016)
based on a probability-measure-independent transla-
tion of PpCTL into pCTL. The theorem for embed-
ding PpCTL into pCTL was proven using this trans-
Towards Locative Inconsistency-tolerant Hierarchical Probabilistic CTL Model Checking: Survey and Future Work
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