Language outputs

The programs DRFLA for vapor-liquid and DRELI for liquid-liquid calculations are written in FORTRAN IV source language for the CDC 6400 of the Computer Center, University of California, Berkeley. Minor modifications, mostly with regard to input and output, will be required for implementation on most other computer systems. 

As was said in the introduction (Section 2.1), chemical structures are the universal and the most natural language of chemists, but not for computers. Computers woi k with bits packed into words or bytes, and they perceive neither atoms noi bonds. On the other hand, human beings do not cope with bits very well. Instead of thinking in terms of 0 and 1, chemists try to build models of the world of molecules. The models ai e conceptually quite simple 2D plots of molecular sti uctures or projections of 3D structures onto a plane. The problem is how to transfer these models to computers and how to make computers understand them. This communication must somehow be handled by widely understood input and output processes. The chemists way of thinking about structures must be translated into computers internal, machine representation through one or more intermediate steps or representations (sec figure 2-23, The input/output processes defined... 

And last not least, we will have to see further improvements in the graphical user interfaces of software systems and the retrieval systems of databases in order to make software and databases more acceptable to the chemical community at large. Software and databases should speak the language a chemist is used to, with hand-drawn chemical structures and reaction equations, or even imderstand the spoken word - and only provide the desired information selectively, not buried in a phe of unnecessary output. 

Japan switch to universal pubHcation, output rose quickly above 100,000/yr (- SSO, 000/yr in 1992—1994) language and numbers make quaHty documen-tation a substantial problem... 

Given an automaton M that starts in state CTi, and any finite string s A, a, s) will represent the final output state that J<4 will enter after having processed s, one symbol at a time, from left to right. J<4 is said to accept the word s if ai,s) E the word s is rejected if and only if it is not accepted. Finally, we may define the language C JA) accepted by M as the set of all words s A that are accepted by Ad. A language C is called regular if there is a finite automaton Ad that accepts it. 

It is thus very important that the output of any simulation is checked, using other integration methods. Most simulation languages allow a choice of integration routine which can be made best on the basis of experience. It is... 

The assembly of numerical techniques, bookkeeping, and control languages that represents the model from acceptance of input data and instruction to delivery of output. 

DEFINITION For a monadic scheme P with a single output variable, the value language of P is the language... 

THEOREM 3.1H Let P be a monadic free scheme with one output variable z. Then the value language L(P) Is regular. 

If two schemas are strongly equivalent they must give the same output under all interpretations and all inputs and hence under all free interpretations thus the value languages must certainly be the same. If S is an extension of S - that is, whenever (S, I,a) converges, (S,I,a) converges and val(S,I,a) = val(S, I,a)... 

Write the spec informally. State in natural language what is required of it. Think in terms of outputs, effects on external objects, and the initial and final internal state. Think also of preconditions — interpreted precisely as the conditions under which this particular postcondition make sense, action return (book) pre — book is lent to someone... 

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