10: Sequential Composition and Conditional Statements in .NET Integrating gs1 datamatrix barcode in .NET 10: Sequential Composition and Conditional Statements 10: Sequential Composition and Conditional StatementsData Matrix Barcodes barcode library on .netusing barcode encoder for .net control to generate, create datamatrix image in .net applications.and then extracting the first k entries. The amount of fuel that a car consumes on a journey of k kilometres is computed by determining the number of litres consumed per kilometre and then multiplying this amount by fc. Counting the proportion of times that a particular letter occurs in the words in a text say the proportion of words in this text that contain the letter 'e' is computed by counting the total number of words in the text and, of these, the number that contain the given letter, and then finally dividing the latter by the former. This problem-solving strategy is captured in programming terms by the sequential composition of statements, here denoted by an infix semicolon. Hoare triples are used to provide the mathematical basis for the strategy. Suppose a programming problem is specified by giving a precondition P and postcondition Q. We are required to construct a program statement S to satisfyData Matrix ECC200 scanner in .netUsing Barcode decoder for Visual Studio .NET Control to read, scan read, scan image in Visual Studio .NET applications.{P}5{Q} Visual Studio .NET bar code maker for .netusing vs .net toincoporate bar code with asp.net web,windows applicationWe can decompose this problem by inventing a suitable intermediate assertion R and then constructing program statements 51 and S2 such thatBuild barcode in .netusing .net crystal toget bar code in asp.net web,windows application{P}S1 { R }Control data matrix barcode image with visual c#generate, create ecc200 none in .net c# projectsand { R } S2 { Q } .Control data matrix data for .net 2d data matrix barcode data in .netExamples of intermediate assertions are 'the deck of cards is sorted' (in the case of finding the best k entries in a deck of cards), 'I pk is the number of litres consumed per kilometre' (in the case of computing fuel consumption over a given number of kilometres), or 'w is the number of words in the text and I is the number of such words containing the given letter' (in the case of counting the proportion of times that a particular letter occurs in a sequence of words). The sequential composition SI;52 of statements 51 and 52 is executed by first executing statement 51 and then statement 52. If 51 has been constructed to satisfy {P}51 { R } , (10.1)2d Data Matrix Barcode barcode library for vbusing .net torender barcode data matrix in asp.net web,windows applicationit means that, if execution of 51 is begun in a state satisfying P, termination is guaranteed in a state satisfying R. Also, if 52 has been constructed to satisfyBarcode barcode library with .netuse visual studio .net crystal barcode implement todisplay bar code with .net{ R } 52 { Q } , (10.2).net Framework denso qr bar code implement with .netusing .net toproduce qr code in asp.net web,windows applicationit means that, if execution of 52 is begun in a state satisfying R, termination is guaranteed in a state satisfying Q. Clearly then, if execution of 51; 52 is begun in a state satisfying P, termination is guaranteed in a state satisfying Q. That is, given (10.1) and (10.2), it is the case that.NET code128b encoder on .netuse .net code 128c printer toassign code 128 code set b with .net{ P } 51;52 { Q } . (10.3)Create 2d barcode on .netgenerate, create 2d matrix barcode none for .net projects10.2 The skip Statement Code 2 Of 7 encoding in .netusing barcode writer for .net vs 2010 control to generate, create uss codabar image in .net vs 2010 applications.This is the rule of sequential composition: for all statements 51 and S2 and all assertions P, Q and R, [Sequence] { P } SI ;S2 { Q } <= { P } SI { R } A { R } S2 { Q } , (10.4)scanning datamatrix in .netUsing Barcode reader for .net framework Control to read, scan read, scan image in .net framework applications.We have introduced the rule of sequential composition in terms of inventing a suitable intermediate assertion R. This is just one way the rule may be used. Another way is that we invent a program statement 51 that we think may be of use in solving the given programming problem. From the specification of 51, we calculate a postcondition R that is guaranteed to hold after executing 51 beginning in a state satisfying P. Finally, we solve the problem of constructing a program statement 52 that will guarantee the postcondition Q if execution of it is begun in a state satisfying precondition JR. Symmetrically, we may invent a program statement 52 that we think may be of use in solving the given programming problem. From the specification of 52, we calculate a precondition -R that will guarantee Q after executing 52. Finally, we solve the problem of constructing a program statement 51 that will guarantee the postcondition R if execution of it is begun in a state satisfying precondition P. These three different strategies (first inventing R, first inventing 51, or first inventing 52) are interrelated but it can be helpful for the more difficult problems to keep them separate in one's mind. It is difficult to give realistic but simple examples at this stage. An example combining the rule of sequential composition with the construction of conditional statements is discussed in Section 10.6.Control ansi/aim code 128 data in .net ansi/aim code 128 data for .netBar Code encoder in fontusing font toembed barcode in asp.net web,windows applicationEmbed pdf417 in word documentsgenerate, create pdf417 none in office word projectsControl pdf417 data for .net pdf 417 data in .net