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Write a program that checks if the given logical expression is a tautology. The logical expression is a tautology if it is always true, regardless of logical value of its variables.
On the first line there is the number of expressions to check (at most 35). The expression is in a prefix notation, that means that operator precedes its arguments. The following logical operators will be used:
C - and D - or I - implies E - if, and only if N - not
The variables will be lowercase letters (a-z). There will be no more than 16 different letters in the expression. The length of the expression will not exceed 111 characters.
For each expression write one word: YES if it is a tautology, NO in other case.
Sample input: 7 IIpqDpNp NCNpp Iaz NNNNNNNp IIqrIIpqIpr Ipp Ezz Sample output: YES YES NO NO YES YES YES
|Time Limit:||0.949153 sec|
|Source Limit:||50000 Bytes|
|Languages:||C, CPP14, JAVA, PYTH, PYTH 3.6, PYPY, CS2, PAS fpc, PAS gpc, RUBY, PHP, GO, NODEJS, HASK, rust, SCALA, swift, D, PERL, FORT, WSPC, ADA, CAML, ICK, BF, ASM, CLPS, PRLG, ICON, SCM qobi, PIKE, ST, NICE, LUA, BASH, NEM, LISP sbcl, LISP clisp, SCM guile, JS, ERL, TCL, kotlin, TEXT, SCM chicken, PYP3, CLOJ, COB, FS|
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