lps2lts-dist(1)

SYNOPSIS

lps2lts-dist [OPTIONS]… input.lps [output.fmt]

DESCRIPTION

lps2lts-dist performs a reachability analysis on a specification provided in input.lps. Specifications are in lps format and are commonly generated by mcrl22lps(1). output.fmt specifies the name of the output archive. The desired format is deduced from the filename extension. Available file formats are described blow.

Using the option --workers=N, this tool starts the command mpirun silently in the background with the suitable options, i.e. -np 4. Alternatively, one may wish to call mpirun with additional options. This can be done using the --mpi option, e.g.:

mpirun -np 4 -mca btl tcp,self {manname} --mpi

OPTIONS

--nice=LEVEL: Set the nice level of all worker processes. This is useful when running on other people’s workstations.
--write-state: Write the full state vector.
--filter=<patternlist>: Select the labels to be written to file from the state vector elements, state labels and edge labels. The argument is a semicolon separated list of shell file patterns. Each pattern may be prefixed with "!" to exclude a set of labels. If none of the patterns matches the default is to exclude the label. Hence, all labels starting with an "x" are specified as "x*". The complement all labels, except those starting with an "x" are specified as "!x*;*".
--cost=<edge label>: The given edge labels defines the cost of an edge. Based on this cost, the lowest cost for reaching every state is computed. Moreover, the order in which states are explored is such that lower cost states are explored before higher costs ones. The levels reported when this options is in effect are cost levels. The counter-example traces are guaranteed to be a lowest cost path. However, the length of the trace may not be minimal.
-n, --no-exit: Do not exit when an error is found. Just count errors. Error counts are printed with -v.
-d, --deadlock: Find state with no outgoing transitions. Returns with exit code 1 if a deadlock is found, 0 or 255 (error) otherwise.
-i, --invariant=PREDFILE|PREDEXPRESSION: Find state where the invariant is violated. The file PREDFILE contains an expression in a simple predicate language (see ltsmin-pred(5)). Its contents can also be entered directly as a PREDEXPRESSION. Returns with exit code 1 if a violation is found, 0 or 255 (error) otherwise.
-a, --action=STRING: Find state with an outgoing transition of type STRING. Returns with exit code 1 if the action is found, 0 or 255 (error) otherwise.
--trace='FILE'.gcf: When finding a deadlock state or a transition labelled with a certain action, write a trace to 'FILE'.gcf, beginning from the initial state. Traces can be pretty-printed with ltsmin-printtrace(1).

mCRL2 Options

--mcrl2=OPTIONS: Pass options to the mCRL2 library. Defaults to "--rewriter=jittyc".

The "--rewriter=<rewriter>" option is the only recognized option. Possible rewriters are jitty and jittyc.
--mcrl2-finite-types: Use mCRL2 finite type information.

Enabling this option may cause premature termination in case non-normal-form instances of finite types occur in the state space. This will be the case, e.g., when the specification has been pre-processed using lpsparunfold(1).
--mcrl2-readable-edge-labels: Use human readable edge labels.

Enabling this option may cause problems during bisimulation reduction, e.g., the edge labels l(0) with 0 of type Nat and l(0) with 0 of type Pos will be mapped to the same string.
-n, --no-exit: Do not exit when an error is found. Just count errors. Error counts are printed with -v.
-d, --deadlock: Find state with no outgoing transitions. Returns with exit code 1 if a deadlock is found, 0 or 255 (error) otherwise.
-i, --invariant=PREDFILE|PREDEXPRESSION: Find state where the invariant is violated. The file PREDFILE contains an expression in a simple predicate language (see ltsmin-pred(5)). Its contents can also be entered directly as a PREDEXPRESSION. Returns with exit code 1 if a violation is found, 0 or 255 (error) otherwise.
-a, --action=STRING: Find state with an outgoing transition of type STRING. Returns with exit code 1 if the action is found, 0 or 255 (error) otherwise.
--trace='FILE'.gcf: When finding a deadlock state or a transition labelled with a certain action, write a trace to 'FILE'.gcf, beginning from the initial state. Traces can be pretty-printed with ltsmin-printtrace(1).

PINS Options

--labels

Print state variable, type and value names, and state and action labels. Then exit. Useful for writing predicate (--invariant), LTL (--ltl), CTL/CTL* (--ctl), and mu-calculus (--mu) expressions.

--matrix

Print the dependency matrix and exit.

-c, --cache

Enable caching of greybox calls.

If this option is used, the state space generator makes calls to the short version of the greybox next-state function and memoizes the results. If the next-state function is expensive this will yield substantial speedups.

--pins-guards

Use guards in combination with the long next-state function to speed up the next-state function.

--allow-undefined-edges

Allow values for edge variables in atomic predicates to be unreachable.

--allow-undefined-values

Allow undefined values in atomic predicates for enums.

-r, --regroup=SPEC

Enable regrouping optimizations on the dependency matrix.

SPEC is a comma-separated sequence of transformations <(T,)+> which are applied in this order to the dependency matrix. The following transformations T are available:

gs

Group Safely; macro for "gc,gr,cw,rs"; almost always a win.

ga

Group Aggressively (row subsumption); macro for "gc,rs,ru,cw,rs"; can be a huge win, but in some cases causes slower state space generation.

gsa

Group Simulated Annealing; macro for "gc,gr,csa,rs"; almost always a win; usually better than gs.

gc

Group Columns; macro for "cs,cn".

gr

Group Rows; macro for "rs,rn".

cs

Column Sort; sort columns lexicographically.

cn

Column Nub; (temporarily) group duplicate columns, thereby making ca more tractable. Requires cs.

cw

Column sWap; minimize distance between columns by swapping them heuristically. This reordering improves performance of the symbolic data structures.

ca

Column All permutations; try to find the column permutation with the best cost metric. Potentially, this is an expensive operation.

csa

Column Simulated Annealing; minimize distance between columns by swapping them using simulated annealing.

rs

Row Sort; sort rows lexicographically.

rn

Row Nub; remove duplicate rows from the dependency matrix. This is always a win. Requires rs.

ru

Row sUbsume; try to remove more rows than nubbing, thereby trading speed for memory. Requires rs.

w2W

Over-approximate all must-write to may-write. May-write supports the copy (-) dependency.

r2+

Over-approximate read to read+write. Allows read dependencies to also subsume write dependencies.

w2+

Over-approximate must-write to read+write. Allows must-write dependencies to also subsume read dependencies.

W2+

Over-approximate may-write to read+write. Allows must-write dependencies to also subsume read dependencies.

-2r

Over-approximate copy to read. May be useful for testing whether the dependency matrix is correct.

rb4w

Use special heuristics to move read dependencies before write dependences. Often a win in symbolic state space generation.

mm

Writes metrics of the selected (sr, sw, sc) matrix to stdout. The following metrics are printed:

Event span: the total distance between the minimum and maximum column of rows.
Normalized event span: the event span divided by the size of the matrix (rows x columns).
Weighted event span: the weighted event span, the event span, including a moment signifying the location of the span. See, Siminiceanu et al., we use moment 1.
Normalized weighted event span: the weighted event span divided by the size of the matrix (rows x column).

sr

Select the read matrix for cs, csa, cw, ca, rs, bcm, bs, bk, vcm, vacm, vgps and mm.

sw

Select the write matrix (default) for cs, csa, cw, ca, rs, bcm, bs, bk, vcm, vacm, vgps and mm. The write matrix is the default selection, because only write dependencies can create new nodes in decision diagrams. A bad variable order in the write matrix thus leads to a large number of peak nodes during reachability analysis. A bad variable order in the read matrix can also lead to a slow reachability analysis, but typically not as severe as a bad variable order in the write matrix. Slow reachability analysis due to a bad variable order in the read matrix causes many recursive calls to the relational product operation. Typically it is best that read dependencies are moved to the top DD level, thus left most in the read matrix.

sc

Select the combined matrix for cs, csa, cw, ca, rs, bcm, bs, bk, vcm, vacm, vgps and mm. The combined matrix is the logical or of the read and write matrix.

bg

Use a bipartite graph (default) for bcm, bk, bs, vcm, vacm and vgps.

tg

Create a total graph of the bipartite graph for bcm, bk, bs, vcm, vacm and vgps. This adds more vertices and edges thus increasing computation time, but sometimes provides a better ordering.

Below, the sparse matrix algorithms prefixed with b are only available when LTSmin is compiled with Boost. Algorithms prefixed with v are only available when LTSmin is compiled with ViennaCL.

bcm: Apply Boost’s Cuthill-McKee ordering.
bk: Apply Boost’s King ordering.
bs: Apply Boost’s Sloan ordering.
vcm: Apply ViennaCL’s Cuthill-McKee ordering.
vacm: Apply ViennaCL’s advanced Cuthill-McKee ordering.
vgps: Apply ViennaCl’s Gibbs-Poole-Stockmeyer ordering.
f: Apply FORCE ordering.

--row-perm=PERM

Apply row permutation PERM, where PERM is a sequence of row numbers, separated by a comma. E.g. the vector 2,1,0 will swap row 2 with row 0.

--col-perm=PERM

Apply column permutation PERM, where PERM is a sequence of column numbers, separated by a comma. E.g. the vector 2,1,0 will swap column 2 with column 0.

--col-ins=PAIRS

Insert columns before other columns in the dependency matrix.

PAIRS is a comma-separated sequence of pairs <(C.C,)+>'. E.g. --col-ins=1.0 will insert column 1 before column 0. Each pair contains a source column C and a target column C'. During the application of the whole sequence, C will always be the column number that corresponds with the column before the application of the whole sequence. The column number C' will always be the column during the application of the whole sequence. This means that in for example --col-ins=2.0,1.0, first column 2 is inserted at position 0, then column 1 is inserted at position 0. The result will be that the original column 2 will be at position 1. Another important detail is that when --col-ins is used, all source columns will temporarily be "removed" during reordering from the dependency matrix, i.e. when the -r,--regroup option is given. After reordering is done, the columns will be inserted at the desired target position. In other words, reordering algorithms given by the option -r,--regroup, will only be applied on the dependency matrix with source columns removed.

--sloan-w1=WEIGHT1

Use WEIGHT1 as the first weight for the Sloan algorithm, see https://www.boost.org/doc/libs/1_66_0/libs/graph/doc/sloan_ordering.htm.

--sloan-w2=WEIGHT2

Use WEIGHT2 as the second weight for the Sloan algorithm, see https://www.boost.org/doc/libs/1_66_0/libs/graph/doc/sloan_ordering.htm.

--graph-metrics

Print Boost’s and ViennaCL’s graph metrics (only available when LTSmin is compiled with Boost or ViennaCL).

--regroup-exit

Exit with 0 when regrouping is done.

--regroup-time

Print timing information of each transformation, given in sequence --regroup (-r).

--mucalc=FILE|FORMULA

Compute a parity game for the mu-calculus formula.

The mu-calculus formula is provided in the file FILE or directly as a string FORMULA. The syntax and tool support are described in ltsmin-mucalc(5).

--por=heur|del

Activate partial-order reduction

Partial-Order Reduction (POR) can reduce the state space when searching for deadlocks (-d) or accepting cycles (--ltl). Two POR algorithms are available:

heur: Uses a cost-based heuristic beam-search to find the smallest stubborn set
del: Uses Valmari’s deletion algorithm to find the smallest stubborn set by iteratively removing transitions while maintaining the constraints.

--weak

Use weak commutativity in partial-order reduction. Possibly yielding better reductions.

--leap

Use leaping partial-order reduction, by combining several disjoint stubborn sets sequentially.

Environment Variables

LTSmin supports the following list of environment variables.

Table 1. Environment Variables:
Name	Unit	Description
LTSMIN_MEM_SIZE	bytes	Sets the amount of system memory to the given value.
LTSMIN_NUM_CPUS	constant	Sets the amount of CPUs to the given value.

The variables LTSMIN_MEM_SIZE, and LTSMIN_NUM_CPUS are particularly relevant when neither sysconf(3) nor cgroups(7) is able to properly detect these limits, e.g. when LTSmin runs on Travis CI in a docker container.

LTS I/O Options

--block-size=BYTES: Size of a block in bytes. Defaults to 32,768.
--cluster-size=BLOCKS: Number of blocks in a cluster. Defaults to 32.

Hybrid Runtime Options

The Hybrid Runtime Environment provides startup options for several parallel architectures.

Posix threads options

If the application supports it and Posix threads are supported by the OS then the following option is available:

--threads[=count]: Start count worker threads. The default count is the number of CPU’s in the system.

Posix processes options

If the application supports it and Posix shared memory is supported by the OS then the following option is available:

--procs[=count]: Fork count worker processes. The default count is the number of CPUs in the system.

Note that MacOS X only supports Posix shared memory from version 10.7 (Lion) onwards.

MPI options

If the application supports it and MPI support was compiled into the binary then the following options are available:

--workers=count: Start the program with count MPI workers.
--mpirun=mpirun arguments: Invoke mpirun with the given arguments.
--mpi: Ignore --workers and --mpirun options and start the MPI runtime.

General Options

-v: Increase the level of verbosity
-q: Be quiet; do not print anything to the terminal.
--debug=file: Enable debugging output for file.
--version: Print version string of this tool.
-h, --help: Print help text
--usage: Print short usage summary.
--stats: Enable statistics gathering/printing.
--timeout=INT: Terminate after the given amount of seconds.
--where: Include file and line number in debug messages.
--when: Include the wall time since program start in all messages.

File Formats

The following file formats are supported:

Directory format (*.dir, *.dz and *.gcf)
Vector format (*.dir, *.gcd, *.gcf)
Binary Coded Graphs (*.bcg)
Aldebaran Format (*.aut)
FSM Format (*.fsm)
MRMC/Prism (*.tra+*.lab)
PGSolver format (*.pg)

If a tool operates in streaming mode then support for file formats is limited, as can be seen in the following table:

Format	Streaming mode	Load/Store mode
DIR	R/W	R/W
VEC	R/W	R/W
BCG	W	R/W
AUT	W	R/W
FSM	W	W
TRA	-	R/W
PG	-	W

The directory format uses multiple files to store an LTS. The various extension explain how these files are stored in the underlying file system. The *.dir format uses multiple files in a directory without compression. If the LTS has one edge label, no state labels and does not store state vectors then these files are backwards compatible. Neither the *.dz nor the *.gcf formats are backwards compatible. Both formats use compression. The first uses a directory for the files, second interleaves files into a single file.

If you try to open a *.dir with the old mCRL tools and you get the error message:

wrong file version: 0

then the directory is probably compressed. If that happens then you may convert the directory by typing the command:

ltsmin-convert bad.dir good.dir

EXIT STATUS

0: Successful termination.
1: Counter example found.
255: Some error occurred.

SUPPORT

Send questions, bug reports, comments and feature suggestions to the LTSmin Support Team.

lps2lts-dist(1) Manual Page

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