Proof by Cases/Proof Rule/Technical Note

Technical Note on Proof by Cases

When invoking Proof by Cases in a tableau proof, use the {{ProofByCases}} template:

{{ProofByCases|line|pool|statement|base|start1|end1|start2|end2}}

where:

line is the number of the line on the tableau proof where Proof by Cases is to be invoked

pool is the pool of assumptions (comma-separated list)

statement is the statement of logic that is to be displayed in the Formula column, without the $ ... $ delimiters

base is the line of the tableau proof where the disjunction being eliminated is situated

start1 is the start line of the block of the tableau proof upon which the demonstration of the first disjunct directly depends

end1 is the end line of the block of the tableau proof upon which the demonstration of the first disjunct directly depends

start2 is the start line of the block of the tableau proof upon which the demonstration of the second disjunct directly depends

end2 is the end line of the block of the tableau proof upon which the demonstration of the second disjunct directly depends