Additional mathematical functions for Tcl expressions: function that returns sum of given list

lSum.tcl

#lSum.tcl
#Copyright (c) 2018 Yuji SODE
#These codes are free. You can redistribute and/or modify these codes.
#Additional mathematical functions for Tcl expressions
# - lSum(list): function that returns sum of given list
#   - $list: a numerical list
#Reference
#Iri, M., and Fujino., Y. 1985. Suchi keisan no joshiki (in Japanese). Kyoritsu Shuppan Co., Ltd.
#ISBN 978-4-320-01343-8
proc ::tcl::mathfunc::lSum {list} {
	namespace path {::tcl::mathop};
	set S 0.0;
	set R 0.0;
	set T 0.0;
	foreach e $list {
		set R [+ $R [expr double($e)]];
		set T $S;
		set S [+ $S $R];
		set T [+ $S [expr {-$T}]];
		set R [+ $R [expr {-$T}]];
	};
	return $S;
};

lSum_min.tcl

#=== lSum.tcl (Yuji SODE, 2018): https://gist.github.com/YujiSODE/1f9a4e2729212691972b196a76ba9bd0 ===
#Additional mathematical functions for Tcl expressions
# [References]
# - Iri, M., and Fujino., Y. 1985. Suchi keisan no joshiki (in Japanese). Kyoritsu Shuppan Co., Ltd.; ISBN 978-4-320-01343-8
proc ::tcl::mathfunc::lSum {list} {namespace path {::tcl::mathop};set S 0.0;set R 0.0;set T 0.0;foreach e $list {set R [+ $R [expr double($e)]];set T $S;set S [+ $S $R];set T [+ $S [expr {-$T}]];set R [+ $R [expr {-$T}]];};return $S;};