Maple 9 Learning Guide - Maplesoft

6.4 Evaluation Rules • 205proc(x::algebraic)optionsystem, ‘Copyright (c) 1996 Waterloo Maple\Inc. All rights reserved .‘;try return _Remember(’procname’(args))catch :end try;if nargs ≠ 1 thenerror “expecting 1 argument, got %1”, nargselif type(x, ’complex(float)’) then evalf(’erfi ’(x))elif type(x, ’∞’) thenif type(x, ’cx_infinity’) then undefined + undefined ∗ Ielif type(x, ’undefined ’) thenNumericTools : −ThrowUndefined (x)elif type(x, ’extended _numeric’) then xelif type(R(x), ’∞’) then ∞ + ∞ ∗ Ielse CopySign(I, I(x))end ifelif type(x, ’undefined ’) thenNumericTools : −ThrowUndefined (x, ’preserve’ = ’axes’)elif type(x, ‘ ∗ ‘) and member(I, {op(x)}) then erf(−I ∗ x) ∗ Ielif type(x, ’complex(numeric)’) and csgn(x) < 0 then− erfi(−x)eliftype(x, ‘ ∗ ‘) and type(op(1, x), ’complex(numeric)’)and csgn(op(1, x)) < 0then − erfi(−x)elif type(x, ‘ + ‘) and traperror(sign(x)) = −1 then − erfi(−x)else ’erfi ’(x)end ifend procThe default value of verboseproc is 1.> interface( verboseproc=1 );The ?interface help page explains the possible settings of verboseprocand the other interface variables.One-Level EvaluationLocal variables of a procedure use one-level evaluation. That is, if youassign a local variable, then the result of evaluation is the value most